diff --git a/.flake8 b/.flake8
index 8916c0d8998a1..ed87df8fb1b6f 100644
--- a/.flake8
+++ b/.flake8
@@ -27,21 +27,3 @@ ignore =
 per-file-ignores =
     # These files need tabs for testing.
     test/dygraph_to_static/test_error.py:E101,W191
-    # Temporarily ignore CINN files, it will fix later
-    python/cinn/**:
-        E265,
-    test/cinn/**:
-        E126,
-        E231,
-        E251,
-        E265,
-        E266,
-        E401,
-        E711,
-        W291,
-        W504,
-    paddle/cinn/**:
-        E265,
-    tools/cinn/**:
-        E265,
-        E401,
diff --git a/test/cinn/op_mappers/test_argsort_op.py b/test/cinn/op_mappers/test_argsort_op.py
index d41cee91be93a..a4aad29a4c6eb 100644
--- a/test/cinn/op_mappers/test_argsort_op.py
+++ b/test/cinn/op_mappers/test_argsort_op.py
@@ -47,7 +47,7 @@ def set_op_outputs(self):
         return {'Out': ['int64'], 'Indices': ['int64']}
 
     def skip_check_outputs(self):
-        #'Out' is never used in Paddle API
+        # 'Out' is never used in Paddle API
         return {"Out"}
 
     def test_check_results(self):
diff --git a/test/cinn/ops/test_fill_constant_op.py b/test/cinn/ops/test_fill_constant_op.py
index 1c69f5574b2cc..1ccfc448b18eb 100644
--- a/test/cinn/ops/test_fill_constant_op.py
+++ b/test/cinn/ops/test_fill_constant_op.py
@@ -46,7 +46,7 @@ def prepare_inputs(self):
                         self.value = eval(f"{dtype}(0)")
 
     def build_paddle_program(self, target):
-        if self.dtype == None:
+        if self.dtype is None:
             x = np.full(self.shape, self.value)
             x = paddle.to_tensor(x)
         else:
@@ -56,7 +56,7 @@ def build_paddle_program(self, target):
 
     def build_cinn_program(self, target):
         builder = NetBuilder("fill_constant")
-        if self.dtype == None:
+        if self.dtype is None:
             x = builder.fill_constant(self.shape, self.value, "out")
         else:
             x = builder.fill_constant(self.shape, self.value, "out", self.dtype)
diff --git a/test/cinn/ops/test_zero_dim_tensor.py b/test/cinn/ops/test_zero_dim_tensor.py
index c6a01e3bdd78b..28d8cd94aaa90 100644
--- a/test/cinn/ops/test_zero_dim_tensor.py
+++ b/test/cinn/ops/test_zero_dim_tensor.py
@@ -37,7 +37,7 @@ def cinn_dtype_convert(dtype_str):
 
 
 ##################################
-####  TestElementwiseAddGrad  ####
+#     TestElementwiseAddGrad     #
 ##################################
 # 1) x is 0D, y is 0D
 @OpTestTool.skip_if(
@@ -109,7 +109,7 @@ def init_input(self):
 
 
 ##################################
-#### TestElementwiseBinaryOp  ####
+#    TestElementwiseBinaryOp     #
 ##################################
 @OpTestTool.skip_if(
     not is_compiled_with_cuda(), "x86 test will be skipped due to timeout."
@@ -469,7 +469,7 @@ def cinn_func(self, builder, *args):
 
 
 ######################
-#### TestUnaryOp  ####
+#    TestUnaryOp     #
 ######################
 @OpTestTool.skip_if(
     not is_compiled_with_cuda(), "x86 test will be skipped due to timeout."
@@ -585,7 +585,7 @@ def cinn_func(self, builder, x):
 
 
 #######################
-#### TestSundryOp  ####
+#    TestSundryOp     #
 #######################
 @OpTestTool.skip_if(
     not is_compiled_with_cuda(), "x86 test will be skipped due to timeout."
diff --git a/test/cinn/test_utils.py b/test/cinn/test_utils.py
index ec29b28f9a1f3..45dd9ae629945 100755
--- a/test/cinn/test_utils.py
+++ b/test/cinn/test_utils.py
@@ -97,7 +97,7 @@ def to_test_op(
             )
         for in_data in temp_inputs:
             args.append(runtime.cinn_pod_value_t(in_data))
-        if output_shapes == None:
+        if output_shapes is None:
             correct_result, output_shapes = self.create_target_data(
                 inputs_data, attrs
             )
@@ -142,7 +142,7 @@ def to_test_op(
         fn(args)
 
         out_result = out[len(out) - 1].numpy()
-        if out_index != None:
+        if out_index is not None:
             out_result = out[out_index].numpy()
         np.testing.assert_allclose(out_result, correct_result, atol=1e-4)