diff --git a/e2e/fixtures/auto-nav-sidebar/doc/api/client-api/_meta.json b/e2e/fixtures/auto-nav-sidebar/doc/api/client-api/_meta.json
index d6f2228e4..f0d31f3ee 100644
--- a/e2e/fixtures/auto-nav-sidebar/doc/api/client-api/_meta.json
+++ b/e2e/fixtures/auto-nav-sidebar/doc/api/client-api/_meta.json
@@ -1,9 +1,4 @@
 [
-  {
-    "type": "file",
-    "name": "index",
-    "label": "Client API Overview"
-  },
   {
     "type": "file",
     "name": "api-runtime",
diff --git a/e2e/fixtures/nested-overview/doc/_meta.json b/e2e/fixtures/nested-overview/doc/_meta.json
index 9134f94c0..48c189727 100644
--- a/e2e/fixtures/nested-overview/doc/_meta.json
+++ b/e2e/fixtures/nested-overview/doc/_meta.json
@@ -1,7 +1,12 @@
 [
   {
-    "text": "Guide",
-    "link": "/level1/",
-    "activeMatch": "/level1/"
+    "text": "Basic",
+    "link": "/basic-level-1/",
+    "activeMatch": "/basic-level-1"
+  },
+  {
+    "text": "Index Convention",
+    "link": "/index-convention-level-1/",
+    "activeMatch": "/index-convention-level-1"
   }
 ]
diff --git a/e2e/fixtures/nested-overview/doc/basic-level-1/_meta.json b/e2e/fixtures/nested-overview/doc/basic-level-1/_meta.json
new file mode 100644
index 000000000..705a5318b
--- /dev/null
+++ b/e2e/fixtures/nested-overview/doc/basic-level-1/_meta.json
@@ -0,0 +1,8 @@
+[
+  "index",
+  {
+    "type": "dir",
+    "label": "Level 2",
+    "name": "level-2"
+  }
+]
\ No newline at end of file
diff --git a/e2e/fixtures/nested-overview/doc/level1/level2/index.mdx b/e2e/fixtures/nested-overview/doc/basic-level-1/index.mdx
similarity index 60%
rename from e2e/fixtures/nested-overview/doc/level1/level2/index.mdx
rename to e2e/fixtures/nested-overview/doc/basic-level-1/index.mdx
index 41fc3a5f6..309258797 100644
--- a/e2e/fixtures/nested-overview/doc/level1/level2/index.mdx
+++ b/e2e/fixtures/nested-overview/doc/basic-level-1/index.mdx
@@ -1,3 +1,4 @@
 ---
+title: Level 1
 overview: true
 ---
diff --git a/e2e/fixtures/nested-overview/doc/basic-level-1/level-2/_meta.json b/e2e/fixtures/nested-overview/doc/basic-level-1/level-2/_meta.json
new file mode 100644
index 000000000..125184c0e
--- /dev/null
+++ b/e2e/fixtures/nested-overview/doc/basic-level-1/level-2/_meta.json
@@ -0,0 +1,9 @@
+[
+  "index",
+  "two",
+  {
+    "type": "dir",
+    "name": "level-3",
+    "label": "Level 3"
+  }
+]
diff --git a/e2e/fixtures/nested-overview/doc/level1/level2/level3/index.mdx b/e2e/fixtures/nested-overview/doc/basic-level-1/level-2/index.mdx
similarity index 60%
rename from e2e/fixtures/nested-overview/doc/level1/level2/level3/index.mdx
rename to e2e/fixtures/nested-overview/doc/basic-level-1/level-2/index.mdx
index 41fc3a5f6..aa9d3a4c7 100644
--- a/e2e/fixtures/nested-overview/doc/level1/level2/level3/index.mdx
+++ b/e2e/fixtures/nested-overview/doc/basic-level-1/level-2/index.mdx
@@ -1,3 +1,4 @@
 ---
+title: Level 2
 overview: true
 ---
diff --git a/e2e/fixtures/nested-overview/doc/basic-level-1/level-2/level-3/_meta.json b/e2e/fixtures/nested-overview/doc/basic-level-1/level-2/level-3/_meta.json
new file mode 100644
index 000000000..b96ffa4b4
--- /dev/null
+++ b/e2e/fixtures/nested-overview/doc/basic-level-1/level-2/level-3/_meta.json
@@ -0,0 +1 @@
+["index", "three"]
diff --git a/e2e/fixtures/nested-overview/doc/basic-level-1/level-2/level-3/index.mdx b/e2e/fixtures/nested-overview/doc/basic-level-1/level-2/level-3/index.mdx
new file mode 100644
index 000000000..4964e1a46
--- /dev/null
+++ b/e2e/fixtures/nested-overview/doc/basic-level-1/level-2/level-3/index.mdx
@@ -0,0 +1,4 @@
+---
+title: Level 3
+overview: true
+---
diff --git a/e2e/fixtures/nested-overview/doc/level1/level2/level3/three.mdx b/e2e/fixtures/nested-overview/doc/basic-level-1/level-2/level-3/three.mdx
similarity index 100%
rename from e2e/fixtures/nested-overview/doc/level1/level2/level3/three.mdx
rename to e2e/fixtures/nested-overview/doc/basic-level-1/level-2/level-3/three.mdx
diff --git a/e2e/fixtures/nested-overview/doc/level1/level2/two.mdx b/e2e/fixtures/nested-overview/doc/basic-level-1/level-2/two.mdx
similarity index 100%
rename from e2e/fixtures/nested-overview/doc/level1/level2/two.mdx
rename to e2e/fixtures/nested-overview/doc/basic-level-1/level-2/two.mdx
diff --git a/e2e/fixtures/nested-overview/doc/index-convention-level-1/_meta.json b/e2e/fixtures/nested-overview/doc/index-convention-level-1/_meta.json
new file mode 100644
index 000000000..212ea50b7
--- /dev/null
+++ b/e2e/fixtures/nested-overview/doc/index-convention-level-1/_meta.json
@@ -0,0 +1,8 @@
+[
+  "index",
+  {
+    "type": "dir",
+    "label": "Level 2",
+    "name": "level-2"
+  }
+]
diff --git a/e2e/fixtures/nested-overview/doc/index-convention-level-1/index.mdx b/e2e/fixtures/nested-overview/doc/index-convention-level-1/index.mdx
new file mode 100644
index 000000000..309258797
--- /dev/null
+++ b/e2e/fixtures/nested-overview/doc/index-convention-level-1/index.mdx
@@ -0,0 +1,4 @@
+---
+title: Level 1
+overview: true
+---
diff --git a/e2e/fixtures/nested-overview/doc/index-convention-level-1/level-2/_meta.json b/e2e/fixtures/nested-overview/doc/index-convention-level-1/level-2/_meta.json
new file mode 100644
index 000000000..0a84e05b5
--- /dev/null
+++ b/e2e/fixtures/nested-overview/doc/index-convention-level-1/level-2/_meta.json
@@ -0,0 +1,8 @@
+[
+  "two",
+  {
+    "type": "dir",
+    "name": "level-3",
+    "label": "Level 3"
+  }
+]
diff --git a/e2e/fixtures/nested-overview/doc/index-convention-level-1/level-2/index.mdx b/e2e/fixtures/nested-overview/doc/index-convention-level-1/level-2/index.mdx
new file mode 100644
index 000000000..aa9d3a4c7
--- /dev/null
+++ b/e2e/fixtures/nested-overview/doc/index-convention-level-1/level-2/index.mdx
@@ -0,0 +1,4 @@
+---
+title: Level 2
+overview: true
+---
diff --git a/e2e/fixtures/nested-overview/doc/index-convention-level-1/level-2/level-3/_meta.json b/e2e/fixtures/nested-overview/doc/index-convention-level-1/level-2/level-3/_meta.json
new file mode 100644
index 000000000..54bdf9a8b
--- /dev/null
+++ b/e2e/fixtures/nested-overview/doc/index-convention-level-1/level-2/level-3/_meta.json
@@ -0,0 +1 @@
+["three", "four"]
diff --git a/e2e/fixtures/nested-overview/doc/index-convention-level-1/level-2/level-3/four.mdx b/e2e/fixtures/nested-overview/doc/index-convention-level-1/level-2/level-3/four.mdx
new file mode 100644
index 000000000..0adae572c
--- /dev/null
+++ b/e2e/fixtures/nested-overview/doc/index-convention-level-1/level-2/level-3/four.mdx
@@ -0,0 +1 @@
+# Four
diff --git a/e2e/fixtures/nested-overview/doc/level1/index.mdx b/e2e/fixtures/nested-overview/doc/index-convention-level-1/level-2/level-3/index.mdx
similarity index 100%
rename from e2e/fixtures/nested-overview/doc/level1/index.mdx
rename to e2e/fixtures/nested-overview/doc/index-convention-level-1/level-2/level-3/index.mdx
diff --git a/e2e/fixtures/nested-overview/doc/index-convention-level-1/level-2/level-3/three.mdx b/e2e/fixtures/nested-overview/doc/index-convention-level-1/level-2/level-3/three.mdx
new file mode 100644
index 000000000..fac55f75e
--- /dev/null
+++ b/e2e/fixtures/nested-overview/doc/index-convention-level-1/level-2/level-3/three.mdx
@@ -0,0 +1 @@
+# Three
diff --git a/e2e/fixtures/nested-overview/doc/index-convention-level-1/level-2/two.mdx b/e2e/fixtures/nested-overview/doc/index-convention-level-1/level-2/two.mdx
new file mode 100644
index 000000000..2ef7ae0ba
--- /dev/null
+++ b/e2e/fixtures/nested-overview/doc/index-convention-level-1/level-2/two.mdx
@@ -0,0 +1 @@
+# Two
diff --git a/e2e/tests/auto-nav-sidebar.test.ts b/e2e/tests/auto-nav-sidebar.test.ts
index 2d740439d..f02cce16c 100644
--- a/e2e/tests/auto-nav-sidebar.test.ts
+++ b/e2e/tests/auto-nav-sidebar.test.ts
@@ -53,7 +53,6 @@ test.describe('Auto nav and sidebar test', async () => {
         'Build Config',
         'Extname Config',
         'Nested',
-        'Client API Overview',
         'Runtime API',
         'Components',
         'Commands',
@@ -90,7 +89,16 @@ test.describe('Auto nav and sidebar test', async () => {
 
     const h2 = await page.$$('.overview-index h2');
     const h2Texts = await Promise.all(h2.map(element => element.textContent()));
-    expect(h2Texts.join(',')).toEqual(['Config'].join(','));
+    expect(h2Texts.join(',')).toEqual(
+      [
+        'Basic Config',
+        'Theme Config',
+        'Front Matter Config',
+        'Build Config',
+        'Extname Config',
+        'Nested',
+      ].join(','),
+    );
 
     const h3 = await page.$$('.overview-group_8f375 h3');
     const h3Texts = await Promise.all(h3.map(element => element.textContent()));
@@ -101,7 +109,7 @@ test.describe('Auto nav and sidebar test', async () => {
         'Front Matter Config',
         'Build Config',
         'Extname Config',
-        'Nested',
+        'Nested Config',
       ].join(','),
     );
 
@@ -117,6 +125,7 @@ test.describe('Auto nav and sidebar test', async () => {
         'Default Config',
         'markdown',
         'markdown.remarkPlugins',
+        'Nested H2',
       ].join(','),
     );
   });
@@ -124,7 +133,7 @@ test.describe('Auto nav and sidebar test', async () => {
   test('Should load subpage API Overview correctly - index.md', async ({
     page,
   }) => {
-    await page.goto(`http://localhost:${appPort}/api/client-api/index.html`, {
+    await page.goto(`http://localhost:${appPort}/api/client-api.html`, {
       waitUntil: 'networkidle',
     });
 
diff --git a/e2e/tests/nested-overview.test.ts b/e2e/tests/nested-overview.test.ts
index 85954dafb..506389e30 100644
--- a/e2e/tests/nested-overview.test.ts
+++ b/e2e/tests/nested-overview.test.ts
@@ -22,40 +22,43 @@ test.describe('Nested overview page', async () => {
   test('Should load nested overview page correctly - level 1', async ({
     page,
   }) => {
-    await page.goto(`http://localhost:${appPort}/level1/index.html`, {
+    await page.goto(`http://localhost:${appPort}/basic-level-1/index.html`, {
       waitUntil: 'networkidle',
     });
 
     const h2 = await page.$$('.overview-index h2');
     const h2Texts = await Promise.all(h2.map(element => element.textContent()));
-    expect(h2Texts.join(',')).toEqual(['level2'].join(','));
+    expect(h2Texts.join(',')).toEqual(['Level 2'].join(','));
 
     const h3 = await page.$$('.overview-group_8f375 h3');
     const h3Texts = await Promise.all(h3.map(element => element.textContent()));
-    expect(h3Texts.join(',')).toEqual(['index', 'level3', 'two'].join(','));
+    expect(h3Texts.join(',')).toEqual(['Level 2', 'two', 'Level 3'].join(','));
   });
 
   test('Should load nested overview page correctly - level 2', async ({
     page,
   }) => {
-    await page.goto(`http://localhost:${appPort}/level1/level2/index.html`, {
-      waitUntil: 'networkidle',
-    });
+    await page.goto(
+      `http://localhost:${appPort}/basic-level-1/level-2/index.html`,
+      {
+        waitUntil: 'networkidle',
+      },
+    );
 
     const h2 = await page.$$('.overview-index h2');
     const h2Texts = await Promise.all(h2.map(element => element.textContent()));
-    expect(h2Texts.join(',')).toEqual(['level3', 'two'].join(','));
+    expect(h2Texts.join(',')).toEqual(['two', 'Level 3'].join(','));
 
     const h3 = await page.$$('.overview-group_8f375 h3');
     const h3Texts = await Promise.all(h3.map(element => element.textContent()));
-    expect(h3Texts.join(',')).toEqual(['index', 'three', 'two'].join(','));
+    expect(h3Texts.join(',')).toEqual(['two', 'Level 3', 'three'].join(','));
   });
 
   test('Should load nested overview page correctly - level 3', async ({
     page,
   }) => {
     await page.goto(
-      `http://localhost:${appPort}/level1/level2/level3/index.html`,
+      `http://localhost:${appPort}/basic-level-1/level-2/level-3/index.html`,
       {
         waitUntil: 'networkidle',
       },
diff --git a/packages/theme-default/src/components/Overview/index.tsx b/packages/theme-default/src/components/Overview/index.tsx
index 4dc28cd14..8db5c072b 100644
--- a/packages/theme-default/src/components/Overview/index.tsx
+++ b/packages/theme-default/src/components/Overview/index.tsx
@@ -18,6 +18,7 @@ import {
   useLocaleSiteData,
 } from '../../logic';
 import styles from './index.module.scss';
+import { findItemByRoutePath } from './utils';
 
 interface GroupItem {
   text?: string;
@@ -133,36 +134,6 @@ export function Overview(props: {
     return '';
   };
 
-  const removeIndex = (link: string) => {
-    if (link.endsWith('/index')) {
-      return link.slice(0, -5);
-    }
-    return link;
-  };
-
-  const findItemByRoutePath = (items, routePath, originalItems) => {
-    for (const item of items) {
-      if (withBase(item.link) === routePath) {
-        return [item];
-      }
-
-      if (removeIndex(withBase(item.link)) === routePath) {
-        return items;
-      }
-
-      if (item.items) {
-        const foundItem = findItemByRoutePath(
-          item.items,
-          routePath,
-          originalItems,
-        );
-        if (foundItem) {
-          return foundItem;
-        }
-      }
-    }
-    return originalItems;
-  };
   const { pages } = siteData;
   const overviewModules = pages.filter(page => subFilter(page.routePath));
   let { items: overviewSidebarGroups } = useSidebarData() as {
@@ -181,7 +152,6 @@ export function Overview(props: {
     overviewSidebarGroups = findItemByRoutePath(
       overviewSidebarGroups,
       routePath,
-      overviewSidebarGroups,
     );
   }
 
@@ -227,8 +197,11 @@ export function Overview(props: {
     customGroups ??
     useMemo(() => {
       const group = overviewSidebarGroups
-        .filter(sidebarGroup => {
-          if ('items' in sidebarGroup && sidebarGroup.items) {
+        .filter(normalizedSidebarGroup => {
+          const sidebarGroup = normalizedSidebarGroup as NormalizedSidebarGroup;
+          if (Array.isArray(sidebarGroup?.items)) {
+            console.log(sidebarGroup, 2222);
+
             return (
               sidebarGroup.items.filter(item => subFilter(getChildLink(item)))
                 .length > 0
@@ -242,16 +215,13 @@ export function Overview(props: {
           }
           return false;
         })
-        .map(sidebarGroup => {
+        .map(normalizedSidebarGroup => {
+          const sidebarGroup = normalizedSidebarGroup as NormalizedSidebarGroup;
           let items = [];
-          if ((sidebarGroup as NormalizedSidebarGroup)?.items) {
-            items = (sidebarGroup as NormalizedSidebarGroup)?.items
+          if (sidebarGroup?.items) {
+            items = sidebarGroup?.items
               ?.map(item =>
-                normalizeSidebarItem(
-                  item,
-                  sidebarGroup as NormalizedSidebarGroup,
-                  frontmatter,
-                ),
+                normalizeSidebarItem(item, sidebarGroup, frontmatter),
               )
               .filter(Boolean);
           } else if (isSingleFile(sidebarGroup)) {
diff --git a/packages/theme-default/src/components/Overview/utils.ts b/packages/theme-default/src/components/Overview/utils.ts
new file mode 100644
index 000000000..d0ef1df93
--- /dev/null
+++ b/packages/theme-default/src/components/Overview/utils.ts
@@ -0,0 +1,88 @@
+import {
+  type NormalizedSidebarGroup,
+  type SidebarDivider,
+  type SidebarItem,
+  withBase,
+} from '@rspress/shared';
+import { isSidebarDivider } from '../Sidebar/utils';
+
+function removeIndex(link: string) {
+  if (link.endsWith('/index')) {
+    return link.slice(0, -5);
+  }
+  return link;
+}
+
+/**
+ * @zh_CN 如果 index 在 sidebar items 中, 则返回所有平级 item, 如果 index 在 dir 上, 则返回 items
+ * @example
+ */
+export function findItemByRoutePath(
+  items: (SidebarItem | NormalizedSidebarGroup | SidebarDivider)[],
+  routePath: string,
+): (SidebarItem | NormalizedSidebarGroup)[] {
+  function isRoutePathMatch(
+    item: SidebarItem | NormalizedSidebarGroup | SidebarDivider,
+  ) {
+    if (isSidebarDivider(item)) {
+      return false;
+    }
+    const withBaseUrl = withBase(item.link);
+    const removeIndexUrl = removeIndex(withBaseUrl);
+    const removeBackSlashedRoutePath = routePath.replace(/\/$/, '');
+    return (
+      // FIXME: 😅 we should refactor all the path logic, /index.html / or no /, l
+      withBaseUrl === routePath ||
+      removeIndexUrl === routePath ||
+      withBaseUrl === removeBackSlashedRoutePath ||
+      removeIndexUrl === removeBackSlashedRoutePath
+    );
+  }
+
+  const matchRoutePathItemIndex = items.findIndex(item => {
+    return isRoutePathMatch(item);
+  });
+
+  if (matchRoutePathItemIndex === -1) {
+    return items
+      .map(item => {
+        if (!('items' in item)) {
+          return [];
+        }
+        return findItemByRoutePath(item.items, routePath);
+      })
+      .flat();
+  }
+
+  const matchRoutePathItem = items[matchRoutePathItemIndex] as
+    | SidebarItem
+    | NormalizedSidebarGroup;
+
+  const isArray = (i: unknown): i is Array<unknown> =>
+    Array.isArray(i) && i.length >= 1;
+
+  // 1. if isDir(item) return item.items
+  if ('items' in matchRoutePathItem && isArray(matchRoutePathItem.items)) {
+    // 2. if isDir(item) && item.items is all files, style is different
+    if (matchRoutePathItem.items.every(item => !('items' in item))) {
+      return [matchRoutePathItem];
+    }
+
+    return matchRoutePathItem.items.filter(item => !isSidebarDivider(item)) as (
+      | SidebarItem
+      | NormalizedSidebarGroup
+    )[];
+  }
+
+  // 3. if matchRoutePathItem is a item, return other items in same level (/api/index.md is in the child sidebar)
+  const result = [...items];
+  if (!('items' in matchRoutePathItem)) {
+    result.splice(matchRoutePathItemIndex, 1);
+  }
+  const res = result.filter(item => !isSidebarDivider(item)) as (
+    | SidebarItem
+    | NormalizedSidebarGroup
+  )[];
+
+  return res;
+}
diff --git a/packages/theme-default/src/components/Sidebar/SidebarGroup.tsx b/packages/theme-default/src/components/Sidebar/SidebarGroup.tsx
index 622a7c239..ec342b203 100644
--- a/packages/theme-default/src/components/Sidebar/SidebarGroup.tsx
+++ b/packages/theme-default/src/components/Sidebar/SidebarGroup.tsx
@@ -11,11 +11,8 @@ import { Tag } from '@theme';
 import styles from './index.module.scss';
 import { SidebarItem as SidebarItemComp } from './SidebarItem';
 import { SidebarDivider } from './SidebarDivider';
-import {
-  highlightTitleStyle,
-  isSidebarDivider,
-  type SidebarItemProps,
-} from '.';
+import { highlightTitleStyle, type SidebarItemProps } from '.';
+import { isSidebarDivider } from './utils';
 import { SvgWrapper } from '../SvgWrapper';
 import { renderInlineMarkdown } from '../../logic';
 
diff --git a/packages/theme-default/src/components/Sidebar/index.tsx b/packages/theme-default/src/components/Sidebar/index.tsx
index 314088088..5ad723197 100644
--- a/packages/theme-default/src/components/Sidebar/index.tsx
+++ b/packages/theme-default/src/components/Sidebar/index.tsx
@@ -6,7 +6,6 @@ import {
   type SidebarItem as ISidebarItem,
   type SidebarDivider as ISidebarDivider,
   type SidebarSectionHeader as ISidebarSectionHeader,
-  isExternalUrl,
 } from '@rspress/shared';
 import { routes } from 'virtual-routes';
 import { matchRoutes, useLocation, removeBase } from '@rspress/runtime';
@@ -19,36 +18,11 @@ import type { UISwitchResult } from '../../logic/useUISwitch';
 import { SidebarSectionHeader } from './SidebarSectionHeader';
 
 import styles from './index.module.scss';
-
-export const isSidebarDivider = (
-  item:
-    | NormalizedSidebarGroup
-    | ISidebarItem
-    | ISidebarDivider
-    | ISidebarSectionHeader,
-): item is ISidebarDivider => {
-  return 'dividerType' in item;
-};
-
-export const isSidebarSectionHeader = (
-  item:
-    | NormalizedSidebarGroup
-    | ISidebarItem
-    | ISidebarDivider
-    | ISidebarSectionHeader,
-): item is ISidebarSectionHeader => {
-  return 'sectionHeaderText' in item;
-};
-
-export const isSideBarCustomLink = (
-  item:
-    | NormalizedSidebarGroup
-    | ISidebarItem
-    | ISidebarDivider
-    | ISidebarSectionHeader,
-) => {
-  return 'link' in item && isExternalUrl(item.link);
-};
+import {
+  isSideBarCustomLink,
+  isSidebarDivider,
+  isSidebarSectionHeader,
+} from './utils';
 
 export interface SidebarItemProps {
   id: string;
diff --git a/packages/theme-default/src/components/Sidebar/utils.ts b/packages/theme-default/src/components/Sidebar/utils.ts
new file mode 100644
index 000000000..c52ebefd9
--- /dev/null
+++ b/packages/theme-default/src/components/Sidebar/utils.ts
@@ -0,0 +1,37 @@
+import {
+  isExternalUrl,
+  type NormalizedSidebarGroup,
+  type SidebarItem as ISidebarItem,
+  type SidebarDivider as ISidebarDivider,
+  type SidebarSectionHeader as ISidebarSectionHeader,
+} from '@rspress/shared';
+
+export const isSidebarDivider = (
+  item:
+    | NormalizedSidebarGroup
+    | ISidebarItem
+    | ISidebarDivider
+    | ISidebarSectionHeader,
+): item is ISidebarDivider => {
+  return 'dividerType' in item;
+};
+
+export const isSidebarSectionHeader = (
+  item:
+    | NormalizedSidebarGroup
+    | ISidebarItem
+    | ISidebarDivider
+    | ISidebarSectionHeader,
+): item is ISidebarSectionHeader => {
+  return 'sectionHeaderText' in item;
+};
+
+export const isSideBarCustomLink = (
+  item:
+    | NormalizedSidebarGroup
+    | ISidebarItem
+    | ISidebarDivider
+    | ISidebarSectionHeader,
+) => {
+  return 'link' in item && isExternalUrl(item.link);
+};