diff --git a/mindspore/ccsrc/ir/primitive.cc b/mindspore/ccsrc/ir/primitive.cc
index 6ec27c2567..3526e47f96 100644
--- a/mindspore/ccsrc/ir/primitive.cc
+++ b/mindspore/ccsrc/ir/primitive.cc
@@ -30,17 +30,21 @@
 #include "pybind_api/export_flags.h"
 
 namespace mindspore {
+static ValuePtr PyArgToValue(const py::object &arg) {
+  if (py::isinstance<SignatureEnumKind>(arg) &&
+      py::cast<SignatureEnumKind>(arg) == SignatureEnumKind::kKindEmptyDefaultValue) {
+    return nullptr;
+  }
+  return parse::data_converter::PyDataToValue(arg);
+}
+
 void PrimitivePy::set_signatures(
   std::vector<std::tuple<std::string, SignatureEnumRW, SignatureEnumKind, py::object, SignatureEnumDType>> signatures) {
   signatures_.clear();
   for (auto &signature : signatures) {
-    std::string name;
-    SignatureEnumRW rw;
-    SignatureEnumKind kind;
-    py::object default_value;
-    SignatureEnumDType dtype;
-    std::tie(name, rw, kind, default_value, dtype) = signature;
-    signatures_.emplace_back(Signature(name, rw, kind, default_value, dtype));
+    auto [name, rw, kind, arg_default, dtype] = signature;
+    auto default_value = PyArgToValue(arg_default);
+    signatures_.emplace_back(name, rw, kind, default_value, dtype);
   }
   set_has_signature(true);
 }
diff --git a/mindspore/ccsrc/ir/signature.h b/mindspore/ccsrc/ir/signature.h
index 48be7e0f31..e9a5a2e1ca 100644
--- a/mindspore/ccsrc/ir/signature.h
+++ b/mindspore/ccsrc/ir/signature.h
@@ -16,14 +16,11 @@
 
 #ifndef MINDSPORE_CCSRC_IR_SIGNATURE_H_
 #define MINDSPORE_CCSRC_IR_SIGNATURE_H_
+
 #include <string>
 #include <vector>
-
-#include "pybind11/operators.h"
 #include "ir/value.h"
 
-namespace py = pybind11;
-
 namespace mindspore {
 // Input signature, support type
 enum SignatureEnumRW {
@@ -62,8 +59,10 @@ struct Signature {
   ValuePtr default_value;  // nullptr for no default value
   SignatureEnumDType dtype;
   Signature(const std::string &arg_name, const SignatureEnumRW &rw_tag, const SignatureEnumKind &arg_kind,
-            const py::object &arg_default, const SignatureEnumDType &arg_dtype);
-  Signature(const std::string &arg_name, const SignatureEnumRW &rw_tag, const SignatureEnumKind &arg_kind);
+            const ValuePtr &arg_default, const SignatureEnumDType &arg_dtype)
+      : name(arg_name), rw(rw_tag), kind(arg_kind), default_value(arg_default), dtype(arg_dtype) {}
+  Signature(const std::string &arg_name, const SignatureEnumRW &rw_tag, const SignatureEnumKind &arg_kind)
+      : Signature(arg_name, rw_tag, arg_kind, nullptr, SignatureEnumDType::kDTypeEmptyDefaultValue) {}
 };
 }  // namespace mindspore
 
diff --git a/mindspore/ccsrc/ir/signature.cc b/mindspore/ccsrc/ir/signature_py.cc
similarity index 77%
rename from mindspore/ccsrc/ir/signature.cc
rename to mindspore/ccsrc/ir/signature_py.cc
index 8f312d5b98..2b01b3e579 100644
--- a/mindspore/ccsrc/ir/signature.cc
+++ b/mindspore/ccsrc/ir/signature_py.cc
@@ -15,30 +15,14 @@
  */
 
 #include "ir/signature.h"
-
 #include "pybind11/operators.h"
 #include "pybind_api/api_register.h"
 #include "pipeline/parse/data_converter.h"
 
-namespace mindspore {
-Signature::Signature(const std::string &arg_name, const SignatureEnumRW &rw_tag, const SignatureEnumKind &arg_kind,
-                     const py::object &arg_default, const SignatureEnumDType &arg_dtype)
-    : name(arg_name), rw(rw_tag), kind(arg_kind), dtype(arg_dtype) {
-  if (py::isinstance<SignatureEnumKind>(arg_default) &&
-      py::cast<SignatureEnumKind>(arg_default) == SignatureEnumKind::kKindEmptyDefaultValue) {
-    default_value = nullptr;
-  } else {
-    default_value = parse::data_converter::PyDataToValue(arg_default);
-  }
-}
-
-Signature::Signature(const std::string &arg_name, const SignatureEnumRW &rw_tag, const SignatureEnumKind &arg_kind)
-    : name(arg_name),
-      rw(rw_tag),
-      kind(arg_kind),
-      default_value(nullptr),
-      dtype(SignatureEnumDType::kDTypeEmptyDefaultValue) {}
+namespace py = pybind11;
 
+namespace mindspore {
+// Bind SignatureEnumRW as a python class.
 REGISTER_PYBIND_DEFINE(SignatureEnumRW, ([](const py::module *m) {
                          (void)py::enum_<SignatureEnumRW>(*m, "signature_rw", py::arithmetic())
                            .value("RW_READ", SignatureEnumRW::kRWRead)