diff --git a/paddle/fluid/operators/unsqueeze_op.cc b/paddle/fluid/operators/unsqueeze_op.cc
index 5e089d77f438e3404378af2f80598f926ca729f8..da542aa852b04d99f25d804ea328fd539cc2152e 100644
--- a/paddle/fluid/operators/unsqueeze_op.cc
+++ b/paddle/fluid/operators/unsqueeze_op.cc
@@ -30,9 +30,9 @@ class UnsqueezeOpInferShape : public framework::InferShapeBase {
     const auto &axes = ctx->Attrs().Get<std::vector<int>>("axes");
     const auto &x_dims = ctx->GetInputDim("X");
     // Validity Check: input tensor dims (<6).
-    PADDLE_ENFORCE(static_cast<int>(x_dims.size()) <= 6,
-                   "Invalid dimensions, dynamic dimensions should within "
-                   "[1, 6] dimensions (Eigen limit).");
+    PADDLE_ENFORCE(x_dims.size() <= 6,
+                   "Invalid dimensions, the rank of Input(X) "
+                   "should be in the range of [1, 6] (Eigen limit)");
     auto out_dims = GetOutputShape(axes, x_dims);
     ctx->SetOutputDim("Out", out_dims);
     if (x_dims[0] == out_dims[0]) {
@@ -44,8 +44,8 @@ class UnsqueezeOpInferShape : public framework::InferShapeBase {
 
   static framework::DDim GetOutputShape(const std::vector<int> unsqz_dims,
                                         const framework::DDim &in_dims) {
-    int output_size = static_cast<int>(in_dims.size() + unsqz_dims.size());
-    int cur_output_size = static_cast<int>(in_dims.size());
+    int output_size = in_dims.size() + static_cast<int>(unsqz_dims.size());
+    int cur_output_size = in_dims.size();
     std::vector<int64_t> output_shape(output_size, 0);
 
     // Validity Check: rank range.
@@ -110,12 +110,11 @@ class UnsqueezeOpMaker : public framework::OpProtoAndCheckerMaker {
     AddInput("X", "(Tensor). The input tensor of unsqueeze operator.");
     AddOutput("Out", "(Tensor). The output tensor of unsqueeze operator.");
     AddAttr<std::vector<int>>("axes",
-                              "(std::vector<int>). List of positive integers,"
+                              "(std::vector<int>). List of integers,"
                               " indicate the dimensions to be inserted")
         .AddCustomChecker([](const std::vector<int> &axes) {
-          PADDLE_ENFORCE(
-              !axes.empty(),
-              "The unsqueeze axes information must be set by Attr(axes).");
+          PADDLE_ENFORCE(!axes.empty(),
+                         "Invalid axes, The unsqueeze axes is empty.");
           // Validity Check: axes dims (<6).
           PADDLE_ENFORCE(static_cast<int>(axes.size()) < 6,
                          "Invalid dimensions, dynamic dimensions should within "