diff --git a/python/paddle/fluid/layers/sequence_lod.py b/python/paddle/fluid/layers/sequence_lod.py
index 1758123f0e60874c4a813c2fea0c2553fce71cb9..80dc990af4556f63e4c7ed5607a5f75ffe592f52 100644
--- a/python/paddle/fluid/layers/sequence_lod.py
+++ b/python/paddle/fluid/layers/sequence_lod.py
@@ -1382,19 +1382,18 @@ def sequence_mask(x, maxlen=None, dtype='int64', name=None):
 
     """
 
-    if _non_static_mode():
+    if in_dygraph_mode():
         if not isinstance(dtype, core.VarDesc.VarType):
             dtype = convert_np_dtype_to_dtype_(dtype)
-        if in_dygraph_mode():
-            if maxlen is not None:
-                if isinstance(maxlen, core.eager.Tensor):
-                    attrs = ('out_dtype', dtype)
-                    out = _C_ops.sequence_mask(x, maxlen, *attrs)
-                else:
-                    attrs = ('out_dtype', dtype, 'maxlen', maxlen)
-                    out = _C_ops.sequence_mask(x, None, *attrs)
-                out.stop_gradient = True
-                return out
+        if maxlen is not None:
+            if isinstance(maxlen, core.eager.Tensor):
+                attrs = ('out_dtype', dtype)
+                out = _C_ops.sequence_mask(x, maxlen, *attrs)
+            else:
+                attrs = ('out_dtype', dtype, 'maxlen', maxlen)
+                out = _C_ops.sequence_mask(x, None, *attrs)
+            out.stop_gradient = True
+            return out
 
     helper = LayerHelper('sequence_mask', **locals())
     out = helper.create_variable_for_type_inference(dtype=dtype)
diff --git a/python/paddle/fluid/tests/unittests/test_rnn_decode_api.py b/python/paddle/fluid/tests/unittests/test_rnn_decode_api.py
index bf848357e3195c5c12a2486e33cde2e2e38fbc64..dacb7a5b599579951f663dcf8f84d8354108132b 100644
--- a/python/paddle/fluid/tests/unittests/test_rnn_decode_api.py
+++ b/python/paddle/fluid/tests/unittests/test_rnn_decode_api.py
@@ -716,7 +716,6 @@ class TestBeamSearch(ModuleApiTest):
     def func_check_output(self):
         self.setUp()
         self.make_inputs()
-        self.make_inputs()
         self.check_output()
 
     def test_check_output(self):