diff --git a/tools/diff_api.py b/tools/diff_api.py
index 97c739ed2a5627ad9fd326f206976a4579dc26a3..ec51711d68a155dabdf3125d43fc35bab0b0c944 100644
--- a/tools/diff_api.py
+++ b/tools/diff_api.py
@@ -26,4 +26,10 @@ for each_diff in result:
         print(each_diff)
 
 if error:
+    print(
+        '''If you modify/add/delete the API files, including code and comment, please follow these steps in order to pass the CI:
+    1. cd ${paddle_path}, compile paddle;
+    2. pip install build/python/dist/(build whl package);
+    3. run "python tools/print_signatures.py paddle.fluid, paddle.reader > paddle/fluid/API.spec"'''
+    )
     sys.exit(1)