diff --git a/python/paddle/fluid/dygraph/nn.py b/python/paddle/fluid/dygraph/nn.py
index c0d8ccda379e1..01c051366be88 100644
--- a/python/paddle/fluid/dygraph/nn.py
+++ b/python/paddle/fluid/dygraph/nn.py
@@ -3228,7 +3228,7 @@ def forward(self, input):
         out = self._helper.create_variable_for_type_inference(input.dtype)
         x_shape = self._helper.create_variable_for_type_inference(input.dtype)
         self._helper.append_op(
-            type="flatten2",
+            type="flatten_contiguous_range",
             inputs={"X": input},
             outputs={"Out": out,
                      "XShape": x_shape},
diff --git a/python/paddle/fluid/tests/unittests/test_flatten_2d_op.py b/python/paddle/fluid/tests/unittests/test_flatten_2d_op.py
deleted file mode 100644
index 189a63a086845..0000000000000
--- a/python/paddle/fluid/tests/unittests/test_flatten_2d_op.py
+++ /dev/null
@@ -1,93 +0,0 @@
-#   Copyright (c) 2019 PaddlePaddle Authors. All Rights Reserved.
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#     http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-
-from __future__ import print_function
-
-import unittest
-import numpy as np
-import paddle.fluid as fluid
-from op_test import OpTest
-
-
-class TestFlattenOp(OpTest):
-    def setUp(self):
-        self.op_type = "flatten2"
-        self.init_test_case()
-        self.inputs = {"X": np.random.random(self.in_shape).astype("float64")}
-        self.init_attrs()
-        self.outputs = {
-            "Out": self.inputs["X"].reshape(self.new_shape),
-            "XShape": np.random.random(self.in_shape).astype("float32")
-        }
-
-    def test_check_output(self):
-        self.check_output(no_check_set=["XShape"])
-
-    def test_check_grad(self):
-        self.check_grad(["X"], "Out")
-
-    def init_test_case(self):
-        self.in_shape = (3, 2, 4, 5)
-        self.axis = 1
-        self.new_shape = (3, 40)
-
-    def init_attrs(self):
-        self.attrs = {"axis": self.axis}
-
-
-class TestFlattenOp(TestFlattenOp):
-    def init_test_case(self):
-        self.in_shape = (3, 2, 5, 4)
-        self.axis = 0
-        self.new_shape = (1, 120)
-
-
-class TestFlattenOpWithDefaultAxis(TestFlattenOp):
-    def init_test_case(self):
-        self.in_shape = (10, 2, 2, 3)
-        self.new_shape = (10, 12)
-
-    def init_attrs(self):
-        self.attrs = {}
-
-
-class TestFlattenOpSixDims(TestFlattenOp):
-    def init_test_case(self):
-        self.in_shape = (3, 2, 3, 2, 4, 4)
-        self.axis = 4
-        self.new_shape = (36, 16)
-
-
-class TestFlatten2OpError(unittest.TestCase):
-    def test_errors(self):
-        with fluid.program_guard(fluid.Program(), fluid.Program()):
-            input_data = np.random.random((3, 2, 4, 5)).astype("float64")
-
-        def test_Variable():
-            # the input type must be Variable
-            fluid.layers.flatten(input_data, axis=1)
-
-        self.assertRaises(TypeError, test_Variable)
-
-        def test_type():
-            # dtype must be float32, float64, int8, int32, int64.
-            x2 = fluid.layers.data(
-                name='x2', shape=[3, 2, 4, 5], dtype='float16')
-            fluid.layers.flatten(x2, axis=1)
-
-        self.assertRaises(TypeError, test_type)
-
-
-if __name__ == "__main__":
-    unittest.main()