diff --git a/python/paddle/fluid/layers/nn.py b/python/paddle/fluid/layers/nn.py
index 3e8479acfb995cdc08ba850c9bf96c53fec0ed35..8f873b9ff5bdd9d02753e91af19f507da339c526 100644
--- a/python/paddle/fluid/layers/nn.py
+++ b/python/paddle/fluid/layers/nn.py
@@ -14,7 +14,6 @@
 """
 All layers just related to the neural network.
 """
-
 import os
 import inspect
 import warnings
@@ -127,7 +126,6 @@ __all__ = [
     'log',
     'crop',
     'crop_tensor',
-    'relu6',
     'pow',
     'hard_sigmoid',
     'prelu',
@@ -9580,52 +9578,6 @@ def pad2d(
     return out
 
 
-@deprecated(since="2.0.0", update_to="paddle.nn.functional.relu6")
-def relu6(x, threshold=6.0, name=None):
-    """
-
-    ${comment}
-
-    Args:
-        x(${x_type}): ${x_comment}
-        threshold(float, optional): ${threshold_comment}
-        name(str, optional): The default value is None. Normally there is no
-            need for user to set this property. For more information, please
-            refer to :ref:`api_guide_Name`.
-
-    Returns:
-        output(${out_type}): ${out_comment}
-
-    Examples:
-
-        .. code-block:: python
-
-            import paddle.fluid as fluid
-            import numpy as np
-            in1 = np.array([[-1,0],[2.5,7.8]])
-            with fluid.dygraph.guard():
-                x1 = fluid.dygraph.to_variable(in1)
-                out1 = fluid.layers.relu6(x=x1, threshold=6.0)
-                print(out1.numpy())
-                # [[0.  0. ]
-                #  [2.5 6. ]]
-    """
-    check_variable_and_dtype(x, 'x', ['float16', 'float32', 'float64'], 'relu6')
-
-    helper = LayerHelper('relu6', **locals())
-    out = helper.create_variable_for_type_inference(dtype=x.dtype)
-    helper.append_op(
-        type='relu6',
-        inputs={'X': x},
-        outputs={'Out': out},
-        attrs={
-            'threshold': threshold,
-            'use_mkldnn': _global_flags()["FLAGS_use_mkldnn"],
-        },
-    )
-    return out
-
-
 @templatedoc()
 def pow(x, factor=1.0, name=None):
     """
diff --git a/python/paddle/fluid/tests/unittests/dygraph_to_static/test_mobile_net.py b/python/paddle/fluid/tests/unittests/dygraph_to_static/test_mobile_net.py
index 083345d9db99a4fbdfae516b9a41fb0660b86ec7..af50300be3a1cbf6027461b869c0dd153f88b060 100644
--- a/python/paddle/fluid/tests/unittests/dygraph_to_static/test_mobile_net.py
+++ b/python/paddle/fluid/tests/unittests/dygraph_to_static/test_mobile_net.py
@@ -80,7 +80,7 @@ class ConvBNLayer(fluid.dygraph.Layer):
         y = self._conv(inputs)
         y = self._batch_norm(y)
         if if_act:
-            y = fluid.layers.relu6(y)
+            y = paddle.nn.functional.relu6(y)
         return y
 
 
diff --git a/python/paddle/fluid/tests/unittests/ir/inference/test_mkldnn_elt_act_fuse_pass.py b/python/paddle/fluid/tests/unittests/ir/inference/test_mkldnn_elt_act_fuse_pass.py
index b926a8f71a9d50b63460bb0c6c5e8b4522bdd340..3c2365c29e60cbb05ca0c69838d19102292ab370 100644
--- a/python/paddle/fluid/tests/unittests/ir/inference/test_mkldnn_elt_act_fuse_pass.py
+++ b/python/paddle/fluid/tests/unittests/ir/inference/test_mkldnn_elt_act_fuse_pass.py
@@ -151,8 +151,7 @@ class ElementwiseActivationMkldnnFusePassTest_Add_Relu6(
 ):
     def set_params(self):
         self.operand = fluid.layers.elementwise_add
-        self.act = fluid.layers.relu6
-        self.act_alpha = 5.0
+        self.act = paddle.nn.functional.relu6
 
 
 class ElementwiseActivationMkldnnFusePassTest_Add_Sigmoid(
@@ -244,8 +243,7 @@ class ElementwiseActivationMkldnnFusePassTest_Sub_Relu6(
 ):
     def set_params(self):
         self.operand = fluid.layers.elementwise_sub
-        self.act = fluid.layers.relu6
-        self.act_alpha = 5.0
+        self.act = paddle.nn.functional.relu6
 
 
 class ElementwiseActivationMkldnnFusePassTest_Sub_Sigmoid(
@@ -345,8 +343,7 @@ class ElementwiseActivationMkldnnFusePassTest_Mul_Relu6(
 ):
     def set_params(self):
         self.operand = fluid.layers.elementwise_mul
-        self.act = fluid.layers.relu6
-        self.act_alpha = 5.0
+        self.act = paddle.nn.functional.relu6
 
 
 class ElementwiseActivationMkldnnFusePassTest_Mul_Sigmoid(
diff --git a/python/paddle/fluid/tests/unittests/ir/inference/test_trt_activation_pass.py b/python/paddle/fluid/tests/unittests/ir/inference/test_trt_activation_pass.py
index 80e51dbf26124a4bc42873c5cf0366efc29b09ae..9b6e3e641037d1c237306c38813c3047e84b0f6e 100644
--- a/python/paddle/fluid/tests/unittests/ir/inference/test_trt_activation_pass.py
+++ b/python/paddle/fluid/tests/unittests/ir/inference/test_trt_activation_pass.py
@@ -71,7 +71,7 @@ class TensorRTSubgraphPassLeakyReluTest(TensorRTSubgraphPassActivationTest):
 
 class TensorRTSubgraphPassRelu6Test(TensorRTSubgraphPassActivationTest):
     def append_act(self, x):
-        return fluid.layers.relu6(x)
+        return paddle.nn.functional.relu6(x)
 
 
 class TensorRTSubgraphPassSoftMaxTest(TensorRTSubgraphPassActivationTest):
diff --git a/python/paddle/fluid/tests/unittests/test_activation_op.py b/python/paddle/fluid/tests/unittests/test_activation_op.py
index f460ed58c1d9ccfc02d782c4078b164e3db76628..ddd287a5803189e76d778f8fedfc1a238800645a 100755
--- a/python/paddle/fluid/tests/unittests/test_activation_op.py
+++ b/python/paddle/fluid/tests/unittests/test_activation_op.py
@@ -2074,7 +2074,7 @@ class TestRelu6API(unittest.TestCase):
         paddle.enable_static()
         with fluid.program_guard(fluid.Program()):
             x = fluid.data('X', self.x_np.shape, self.x_np.dtype)
-            out = fluid.layers.relu6(x)
+            out = paddle.nn.functional.relu6(x)
             exe = fluid.Executor(self.place)
             res = exe.run(feed={'X': self.x_np}, fetch_list=[out])
         out_ref = ref_relu6(self.x_np)