diff --git a/python/paddle/fluid/tests/unittests/mlu/test_flatten2_op_mlu.py b/python/paddle/fluid/tests/unittests/mlu/test_flatten2_op_mlu.py
new file mode 100644
index 0000000000000000000000000000000000000000..b5f79a92b190f72402f98dd756a427a3e7cb22d5
--- /dev/null
+++ b/python/paddle/fluid/tests/unittests/mlu/test_flatten2_op_mlu.py
@@ -0,0 +1,113 @@
+#   Copyright (c) 2022 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
+import paddle
+import sys
+sys.path.append("..")
+from op_test import OpTest
+paddle.enable_static()
+
+
+class TestFlattenOp(OpTest):
+    def setUp(self):
+        self.place = paddle.device.MLUPlace(0)
+        self.__class__.use_mlu = True
+        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_with_place(self.place, no_check_set=["XShape"])
+
+    def test_check_grad(self):
+        self.check_grad_with_place(self.place, ["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 TestFlattenOp1(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 TestStaticFlattenInferShapePythonAPI(unittest.TestCase):
+    def execute_api(self, x, axis=1):
+        return fluid.layers.flatten(x, axis=axis)
+
+    def test_static_api(self):
+        paddle.enable_static()
+        main_prog = paddle.static.Program()
+        with paddle.static.program_guard(main_prog, paddle.static.Program()):
+            x = paddle.static.data(
+                name="x", shape=[-1, 3, -1, -1], dtype='float32')
+            out = self.execute_api(x, axis=2)
+        self.assertTrue((-1, -1) == out.shape)
+
+
+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, uint8.
+            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()
diff --git a/python/paddle/fluid/tests/unittests/mlu/test_flatten_contigous_range_op_mlu.py b/python/paddle/fluid/tests/unittests/mlu/test_flatten_contigous_range_op_mlu.py
new file mode 100755
index 0000000000000000000000000000000000000000..8b14494ea09477106814f7af5f44c25abbbe4ca5
--- /dev/null
+++ b/python/paddle/fluid/tests/unittests/mlu/test_flatten_contigous_range_op_mlu.py
@@ -0,0 +1,331 @@
+#   Copyright (c) 2022 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 numpy as np
+import unittest
+import sys
+sys.path.append("..")
+from op_test import OpTest
+import paddle
+import paddle.fluid as fluid
+
+paddle.enable_static()
+
+
+class TestFlattenOp(OpTest):
+    def setUp(self):
+        self.set_mlu()
+        self.op_type = "flatten_contiguous_range"
+        self.place = paddle.MLUPlace(0)
+
+        self.start_axis = 0
+        self.stop_axis = -1
+        self.dtype = np.float64
+        self.init_test_case()
+        self.inputs = {"X": np.random.random(self.in_shape).astype(self.dtype)}
+        self.init_attrs()
+        self.outputs = {
+            "Out": self.inputs["X"].reshape(self.new_shape),
+            "XShape": np.random.random(self.in_shape).astype("float32")
+        }
+
+    def set_mlu(self):
+        self.__class__.use_mlu = True
+
+    def test_check_output(self):
+        self.check_output_with_place(self.place, no_check_set=["XShape"])
+
+    def test_check_grad(self):
+        #pass
+        self.check_grad_with_place(self.place, ["X"], "Out")
+
+    def init_test_case(self):
+        self.in_shape = (3, 2, 5, 4)
+        self.start_axis = 0
+        self.stop_axis = -1
+        self.new_shape = (120)
+
+    def init_attrs(self):
+        self.attrs = {
+            "start_axis": self.start_axis,
+            "stop_axis": self.stop_axis
+        }
+
+
+class TestFlattenOp_1(TestFlattenOp):
+    def init_test_case(self):
+        self.in_shape = (3, 2, 5, 4)
+        self.start_axis = 1
+        self.stop_axis = 2
+        self.new_shape = (3, 10, 4)
+
+    def init_attrs(self):
+        self.attrs = {
+            "start_axis": self.start_axis,
+            "stop_axis": self.stop_axis
+        }
+
+
+class TestFlattenOp_2(TestFlattenOp):
+    def init_test_case(self):
+        self.in_shape = (3, 2, 5, 4)
+        self.start_axis = 0
+        self.stop_axis = 1
+        self.new_shape = (6, 5, 4)
+
+    def init_attrs(self):
+        self.attrs = {
+            "start_axis": self.start_axis,
+            "stop_axis": self.stop_axis
+        }
+
+
+class TestFlattenOp_3(TestFlattenOp):
+    def init_test_case(self):
+        self.in_shape = (3, 2, 5, 4)
+        self.start_axis = 0
+        self.stop_axis = 2
+        self.new_shape = (30, 4)
+
+    def init_attrs(self):
+        self.attrs = {
+            "start_axis": self.start_axis,
+            "stop_axis": self.stop_axis
+        }
+
+
+class TestFlattenOp_4(TestFlattenOp):
+    def init_test_case(self):
+        self.in_shape = (3, 2, 5, 4)
+        self.start_axis = -2
+        self.stop_axis = -1
+        self.new_shape = (3, 2, 20)
+
+    def init_attrs(self):
+        self.attrs = {
+            "start_axis": self.start_axis,
+            "stop_axis": self.stop_axis
+        }
+
+
+class TestFlattenOp_5(TestFlattenOp):
+    def init_test_case(self):
+        self.in_shape = (3, 2, 5, 4)
+        self.start_axis = 2
+        self.stop_axis = 2
+        self.new_shape = (3, 2, 5, 4)
+
+    def init_attrs(self):
+        self.attrs = {
+            "start_axis": self.start_axis,
+            "stop_axis": self.stop_axis
+        }
+
+
+class TestFlattenOpSixDims(TestFlattenOp):
+    def init_test_case(self):
+        self.in_shape = (3, 2, 3, 2, 4, 4)
+        self.start_axis = 3
+        self.stop_axis = 5
+        self.new_shape = (3, 2, 3, 32)
+
+    def init_attrs(self):
+        self.attrs = {
+            "start_axis": self.start_axis,
+            "stop_axis": self.stop_axis
+        }
+
+
+class TestFlattenOp_Float32(TestFlattenOp):
+    def init_test_case(self):
+        self.in_shape = (3, 2, 5, 4)
+        self.start_axis = 0
+        self.stop_axis = 1
+        self.new_shape = (6, 5, 4)
+        self.dtype = np.float32
+
+    def init_attrs(self):
+        self.attrs = {
+            "start_axis": self.start_axis,
+            "stop_axis": self.stop_axis
+        }
+
+
+class TestFlattenOp_int32(TestFlattenOp):
+    def init_test_case(self):
+        self.in_shape = (3, 2, 5, 4)
+        self.start_axis = 0
+        self.stop_axis = 1
+        self.new_shape = (6, 5, 4)
+        self.dtype = np.int32
+
+    def init_attrs(self):
+        self.attrs = {
+            "start_axis": self.start_axis,
+            "stop_axis": self.stop_axis
+        }
+
+    def test_check_grad(self):
+        pass
+
+
+class TestFlattenOp_uint8(TestFlattenOp):
+    def init_test_case(self):
+        self.in_shape = (3, 2, 5, 4)
+        self.start_axis = 0
+        self.stop_axis = 1
+        self.new_shape = (6, 5, 4)
+        self.dtype = np.uint8
+
+    def init_attrs(self):
+        self.attrs = {
+            "start_axis": self.start_axis,
+            "stop_axis": self.stop_axis
+        }
+
+    def test_check_grad(self):
+        pass
+
+
+class TestFlattenOp_int8(TestFlattenOp):
+    def init_test_case(self):
+        self.in_shape = (3, 2, 5, 4)
+        self.start_axis = 0
+        self.stop_axis = 1
+        self.new_shape = (6, 5, 4)
+        self.dtype = np.int8
+
+    def init_attrs(self):
+        self.attrs = {
+            "start_axis": self.start_axis,
+            "stop_axis": self.stop_axis
+        }
+
+    def test_check_grad(self):
+        pass
+
+
+class TestFlattenOp_int64(TestFlattenOp):
+    def init_test_case(self):
+        self.in_shape = (3, 2, 5, 4)
+        self.start_axis = 0
+        self.stop_axis = 1
+        self.new_shape = (6, 5, 4)
+        self.dtype = np.int64
+
+    def init_attrs(self):
+        self.attrs = {
+            "start_axis": self.start_axis,
+            "stop_axis": self.stop_axis
+        }
+
+    def test_check_grad(self):
+        pass
+
+
+class TestFlatten2OpError(unittest.TestCase):
+    def test_errors(self):
+        image_shape = (2, 3, 4, 4)
+        x = np.arange(image_shape[0] * image_shape[1] * image_shape[2] *
+                      image_shape[3]).reshape(image_shape) / 100.
+        x = x.astype('float32')
+
+        def test_ValueError1():
+            x_var = paddle.static.data(
+                name="x", shape=image_shape, dtype='float32')
+            out = paddle.flatten(x_var, start_axis=2, stop_axis=1)
+
+        self.assertRaises(ValueError, test_ValueError1)
+
+        def test_ValueError2():
+            x_var = paddle.static.data(
+                name="x", shape=image_shape, dtype='float32')
+            paddle.flatten(x_var, start_axis=10, stop_axis=1)
+
+        self.assertRaises(ValueError, test_ValueError2)
+
+        def test_ValueError3():
+            x_var = paddle.static.data(
+                name="x", shape=image_shape, dtype='float32')
+            paddle.flatten(x_var, start_axis=2, stop_axis=10)
+
+        self.assertRaises(ValueError, test_ValueError3)
+
+        def test_type():
+            # dtype must be float32, float64, int8, int32, int64, uint8.
+            x2 = np.arange(image_shape[0] * image_shape[1] * image_shape[2] *
+                           image_shape[3]).reshape(image_shape) / 100.
+            x2 = x2.astype('float16')
+            x2_var = paddle.fluid.data(
+                name='x2', shape=[3, 2, 4, 5], dtype='float16')
+            paddle.flatten(x2_var)
+
+        self.assertRaises(TypeError, test_type)
+
+        def test_InputError():
+            out = paddle.flatten(x)
+
+        self.assertRaises(ValueError, test_InputError)
+
+
+class TestStaticFlattenPythonAPI(unittest.TestCase):
+    def execute_api(self, x, start_axis=0, stop_axis=-1):
+        return paddle.flatten(x, start_axis, stop_axis)
+
+    def test_static_api(self):
+        paddle.enable_static()
+        np_x = np.random.rand(2, 3, 4, 4).astype('float32')
+
+        main_prog = paddle.static.Program()
+        with paddle.static.program_guard(main_prog, paddle.static.Program()):
+            x = paddle.static.data(
+                name="x", shape=[2, 3, 4, 4], dtype='float32')
+            out = self.execute_api(x, start_axis=-2, stop_axis=-1)
+
+        exe = paddle.static.Executor(place=paddle.MLUPlace(0))
+        fetch_out = exe.run(main_prog, feed={"x": np_x}, fetch_list=[out])
+        self.assertTrue((2, 3, 16) == fetch_out[0].shape)
+
+
+class TestStaticInplaceFlattenPythonAPI(TestStaticFlattenPythonAPI):
+    def execute_api(self, x, start_axis=0, stop_axis=-1):
+        return x.flatten_(start_axis, stop_axis)
+
+
+class TestFlattenPython(unittest.TestCase):
+    def test_python_api(self):
+        image_shape = (2, 3, 4, 4)
+        x = np.arange(image_shape[0] * image_shape[1] * image_shape[2] *
+                      image_shape[3]).reshape(image_shape) / 100.
+        x = x.astype('float32')
+
+        def test_InputError():
+            out = paddle.flatten(x)
+
+        self.assertRaises(ValueError, test_InputError)
+
+        def test_Negative():
+            paddle.disable_static(paddle.MLUPlace(0))
+            img = paddle.to_tensor(x)
+            out = paddle.flatten(img, start_axis=-2, stop_axis=-1)
+            return out.numpy().shape
+
+        res_shape = test_Negative()
+        self.assertTrue((2, 3, 16) == res_shape)
+
+
+if __name__ == "__main__":
+    unittest.main()
diff --git a/python/paddle/fluid/tests/unittests/mlu/test_flatten_op_mlu.py b/python/paddle/fluid/tests/unittests/mlu/test_flatten_op_mlu.py
new file mode 100644
index 0000000000000000000000000000000000000000..a5503de7cca24fb25e2f3050ee848660c7ad2df4
--- /dev/null
+++ b/python/paddle/fluid/tests/unittests/mlu/test_flatten_op_mlu.py
@@ -0,0 +1,77 @@
+#   Copyright (c) 2022 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 sys
+sys.path.append("..")
+from op_test import OpTest
+
+import paddle
+import paddle.fluid as fluid
+paddle.enable_static()
+
+
+class TestFlattenOp(OpTest):
+    def setUp(self):
+        self.place = paddle.device.MLUPlace(0)
+        self.__class__.use_mlu = True
+        self.op_type = "flatten"
+        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)}
+
+    def test_check_output(self):
+        self.check_output_with_place(self.place)
+
+    def test_check_grad(self):
+        self.check_grad_with_place(self.place, ["X"], "Out")
+
+    def init_test_case(self):
+        self.in_shape = (3, 2, 2, 10)
+        self.axis = 1
+        self.new_shape = (3, 40)
+
+    def init_attrs(self):
+        self.attrs = {"axis": self.axis}
+
+
+class TestFlattenOp1(TestFlattenOp):
+    def init_test_case(self):
+        self.in_shape = (3, 2, 2, 10)
+        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)
+
+
+if __name__ == "__main__":
+    unittest.main()