diff --git a/paddle/fluid/prim/api/composite_backward/composite_double_backward_api.h b/paddle/fluid/prim/api/composite_backward/composite_double_backward_api.h
index a7479bc7166694..8cabcd812d1d34 100644
--- a/paddle/fluid/prim/api/composite_backward/composite_double_backward_api.h
+++ b/paddle/fluid/prim/api/composite_backward/composite_double_backward_api.h
@@ -412,7 +412,8 @@ void multiply_double_grad(const Tensor& x,
       }
 
     } else {
-      x_grad = nullptr;
+      auto dx = full<T>(phi::vectorize(x.dims()), 0.0, x.dtype());
+      set_output<T>(dx, x_grad);
     }
   }
   if (y_grad) {
@@ -433,22 +434,22 @@ void multiply_double_grad(const Tensor& x,
         set_output<T>(dy, y_grad);
       }
     } else {
-      y_grad = nullptr;
+      auto dy = full<T>(phi::vectorize(y.dims()), 0.0, y.dtype());
+      set_output<T>(dy, y_grad);
     }
   }
   if (grad_out_grad) {
+    Tensor ddout;
     if (grad_x_grad && grad_y_grad) {
-      auto ddout = grad_x_grad.get() * y + grad_y_grad.get() * x;
-      set_output<T>(ddout, grad_out_grad);
+      ddout = grad_x_grad.get() * y + grad_y_grad.get() * x;
     } else if (grad_x_grad) {
-      auto ddout = grad_x_grad.get() * y;
-      set_output<T>(ddout, grad_out_grad);
+      ddout = grad_x_grad.get() * y;
     } else if (grad_y_grad) {
-      auto ddout = grad_y_grad.get() * x;
-      set_output<T>(ddout, grad_out_grad);
+      ddout = grad_y_grad.get() * x;
     } else {
-      grad_out_grad = nullptr;
+      ddout = full<T>(phi::vectorize(grad_out.dims()), 0.0, grad_out.dtype());
     }
+    set_output<T>(ddout, grad_out_grad);
   }
 }
 
@@ -461,10 +462,10 @@ void add_double_grad(const Tensor& y,
                      Tensor* grad_out_grad) {
   if (grad_out_grad) {
     // ddout = ddx + ddy
+    Tensor ddout = full<T>(phi::vectorize(grad_out.dims()), 0.0, y.dtype());
     if (!grad_x_grad && !grad_y_grad) {
-      grad_out_grad = nullptr;
+      set_output<T>(ddout, grad_out_grad);
     } else {
-      Tensor ddout = full<T>(phi::vectorize(grad_out.dims()), 0.0, y.dtype());
       if (grad_x_grad) {
         ddout = ddout + grad_x_grad.get();
       }
diff --git a/python/paddle/fluid/backward.py b/python/paddle/fluid/backward.py
index 2a3404d95e0ffc..c737134f474ec1 100755
--- a/python/paddle/fluid/backward.py
+++ b/python/paddle/fluid/backward.py
@@ -2489,9 +2489,11 @@ def calc_gradient_helper(
         block, targets, inputs, block_no_grad_set, op_path_dict
     )
 
-    # only for composite to add grad_op input,
-    # tmp_targets includes targets and other outputs
-    # of the same forward op who create targets
+    # only for composite to add grad_var of the last forward op
+    # who has more than one output, but targets only has one,
+    # so targets_gradients only add one grad_var,
+    # eg: op1 -> op2 -> var1 / var2 targets = var1,
+    # targets_gradients = var1_grad, need to add var2_grad here.
     tmp_targets = targets
 
     if core._is_bwd_prim_enabled():