diff --git a/python/engines/arm/py_arm.h b/python/engines/arm/py_arm.h
new file mode 100644
index 000000000..9e709f351
--- /dev/null
+++ b/python/engines/arm/py_arm.h
@@ -0,0 +1,31 @@
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you 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.
+
+#ifndef _ST_HPC_PPL_NN_PYTHON_ARM_PY_ARM_H_
+#define _ST_HPC_PPL_NN_PYTHON_ARM_PY_ARM_H_
+
+#include "pybind11/pybind11.h"
+
+namespace ppl { namespace nn { namespace python { namespace arm {
+
+void RegisterEngineFactory(pybind11::module*);
+void RegisterEngineOptions(pybind11::module*);
+void RegisterEngine(pybind11::module*);
+
+}}}}
+
+#endif
diff --git a/python/engines/cuda/py_cuda.h b/python/engines/cuda/py_cuda.h
new file mode 100644
index 000000000..f26d855b3
--- /dev/null
+++ b/python/engines/cuda/py_cuda.h
@@ -0,0 +1,31 @@
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you 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.
+
+#ifndef _ST_HPC_PPL_NN_PYTHON_CUDA_PY_CUDA_H_
+#define _ST_HPC_PPL_NN_PYTHON_CUDA_PY_CUDA_H_
+
+#include "pybind11/pybind11.h"
+
+namespace ppl { namespace nn { namespace python { namespace cuda {
+
+void RegisterEngineFactory(pybind11::module*);
+void RegisterEngineOptions(pybind11::module*);
+void RegisterEngine(pybind11::module*);
+
+}}}}
+
+#endif
diff --git a/python/engines/riscv/py_riscv.h b/python/engines/riscv/py_riscv.h
new file mode 100644
index 000000000..933809954
--- /dev/null
+++ b/python/engines/riscv/py_riscv.h
@@ -0,0 +1,31 @@
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you 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.
+
+#ifndef _ST_HPC_PPL_NN_PYTHON_RISCV_PY_RISCV_H_
+#define _ST_HPC_PPL_NN_PYTHON_RISCV_PY_RISCV_H_
+
+#include "pybind11/pybind11.h"
+
+namespace ppl { namespace nn { namespace python { namespace riscv {
+
+void RegisterEngineFactory(pybind11::module*);
+void RegisterEngineOptions(pybind11::module*);
+void RegisterEngine(pybind11::module*);
+
+}}}}
+
+#endif
diff --git a/python/engines/x86/py_x86.h b/python/engines/x86/py_x86.h
new file mode 100644
index 000000000..821eb860a
--- /dev/null
+++ b/python/engines/x86/py_x86.h
@@ -0,0 +1,31 @@
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you 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.
+
+#ifndef _ST_HPC_PPL_NN_PYTHON_X86_PY_X86_H_
+#define _ST_HPC_PPL_NN_PYTHON_X86_PY_X86_H_
+
+#include "pybind11/pybind11.h"
+
+namespace ppl { namespace nn { namespace python { namespace x86 {
+
+void RegisterEngineFactory(pybind11::module*);
+void RegisterEngineOptions(pybind11::module*);
+void RegisterEngine(pybind11::module*);
+
+}}}}
+
+#endif
diff --git a/python/models/onnx/py_onnx.h b/python/models/onnx/py_onnx.h
new file mode 100644
index 000000000..196fefecd
--- /dev/null
+++ b/python/models/onnx/py_onnx.h
@@ -0,0 +1,31 @@
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you 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.
+
+#ifndef _ST_HPC_PPL_NN_PYTHON_ONNX_PY_ONNX_H_
+#define _ST_HPC_PPL_NN_PYTHON_ONNX_PY_ONNX_H_
+
+#include "pybind11/pybind11.h"
+
+namespace ppl { namespace nn { namespace python { namespace onnx {
+
+void RegisterRuntimeBuilderResources(pybind11::module*);
+void RegisterRuntimeBuilder(pybind11::module*);
+void RegisterRuntimeBuilderFactory(pybind11::module*);
+
+}}}}
+
+#endif
diff --git a/python/models/pmx/py_pmx.h b/python/models/pmx/py_pmx.h
new file mode 100644
index 000000000..d8121cac5
--- /dev/null
+++ b/python/models/pmx/py_pmx.h
@@ -0,0 +1,33 @@
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you 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.
+
+#ifndef _ST_HPC_PPL_NN_PYTHON_PMX_PY_PMX_H_
+#define _ST_HPC_PPL_NN_PYTHON_PMX_PY_PMX_H_
+
+#include "pybind11/pybind11.h"
+
+namespace ppl { namespace nn { namespace python { namespace pmx {
+
+void RegisterRuntimeBuilderResources(pybind11::module*);
+void RegisterRuntimeBuilder(pybind11::module*);
+void RegisterRuntimeBuilderFactory(pybind11::module*);
+void RegisterLoadModelOptions(pybind11::module*);
+void RegisterSaveModelOptions(pybind11::module*);
+
+}}}}
+
+#endif
diff --git a/python/py_pplnn.cc b/python/py_pplnn.cc
index da520ee80..458323534 100644
--- a/python/py_pplnn.cc
+++ b/python/py_pplnn.cc
@@ -19,40 +19,32 @@
 #include "ppl/nn/common/logger.h"
 using namespace ppl::common;
 
-namespace ppl { namespace nn { namespace python {
-
 #ifdef PPLNN_USE_CUDA
-namespace cuda {
-void RegisterEngineFactory(pybind11::module*);
-void RegisterEngineOptions(pybind11::module*);
-void RegisterEngine(pybind11::module*);
-} // namespace cuda
+#include "engines/cuda/py_cuda.h"
 #endif
 
 #ifdef PPLNN_USE_X86
-namespace x86 {
-void RegisterEngineFactory(pybind11::module*);
-void RegisterEngineOptions(pybind11::module*);
-void RegisterEngine(pybind11::module*);
-} // namespace x86
+#include "engines/x86/py_x86.h"
 #endif
 
 #ifdef PPLNN_USE_RISCV
-namespace riscv {
-void RegisterEngineFactory(pybind11::module*);
-void RegisterEngineOptions(pybind11::module*);
-void RegisterEngine(pybind11::module*);
-} // namespace riscv
+#include "engines/riscv/py_riscv.h"
 #endif
 
 #ifdef PPLNN_USE_ARM
-namespace arm {
-void RegisterEngineFactory(pybind11::module*);
-void RegisterEngineOptions(pybind11::module*);
-void RegisterEngine(pybind11::module*);
-} // namespace arm
+#include "engines/arm/py_arm.h"
+#endif
+
+#ifdef PPLNN_ENABLE_ONNX_MODEL
+#include "models/onnx/py_onnx.h"
+#endif
+
+#ifdef PPLNN_ENABLE_PMX_MODEL
+#include "models/pmx/py_pmx.h"
 #endif
 
+namespace ppl { namespace nn { namespace python {
+
 void RegisterLogger(pybind11::module*);
 void RegisterTensorShape(pybind11::module*);
 void RegisterTensor(pybind11::module*);
@@ -61,27 +53,7 @@ void RegisterEngine(pybind11::module*);
 void RegisterDeviceContext(pybind11::module*);
 void RegisterRuntime(pybind11::module*);
 void RegisterVersion(pybind11::module*);
-
 void RegisterModelOptionsBase(pybind11::module*);
-
-#ifdef PPLNN_ENABLE_ONNX_MODEL
-namespace onnx {
-void RegisterRuntimeBuilderResources(pybind11::module*);
-void RegisterRuntimeBuilder(pybind11::module*);
-void RegisterRuntimeBuilderFactory(pybind11::module*);
-} // namespace onnx
-#endif
-
-#ifdef PPLNN_ENABLE_PMX_MODEL
-namespace pmx {
-void RegisterRuntimeBuilderResources(pybind11::module*);
-void RegisterRuntimeBuilder(pybind11::module*);
-void RegisterRuntimeBuilderFactory(pybind11::module*);
-void RegisterLoadModelOptions(pybind11::module*);
-void RegisterSaveModelOptions(pybind11::module*);
-} // namespace pmx
-#endif
-
 void LoadResources(pybind11::module*);
 
 PYBIND11_MODULE(nn, m) {