diff --git a/python/paddle/fluid/tests/unittests/op_test.py b/python/paddle/fluid/tests/unittests/op_test.py
index bd38bae42e0a6e5aed8f689426c6aa03aaca0843..f077a0286d3e959dcf0298e82d7d0e11d12ac9e7 100644
--- a/python/paddle/fluid/tests/unittests/op_test.py
+++ b/python/paddle/fluid/tests/unittests/op_test.py
@@ -1544,6 +1544,10 @@ class OpTest(unittest.TestCase):
                 grad_outputs = []
                 for grad_out_value in user_defined_grad_outputs:
                     grad_outputs.append(paddle.to_tensor(grad_out_value))
+                # delete the inputs which no need to calculate grad
+                for no_grad_val in no_grad_set:
+                    del (inputs[no_grad_val])
+
                 grad_inputs = paddle.grad(
                     outputs=fluid.layers.utils.flatten(outputs),
                     inputs=fluid.layers.utils.flatten(inputs),