diff --git a/oneflow/core/register/blob.cpp b/oneflow/core/register/blob.cpp
index 04859a1d5fcf616ec5e12d122aaee892b0851a4c..bce1c7c47a36f65fda614f807403c54e92044505 100644
--- a/oneflow/core/register/blob.cpp
+++ b/oneflow/core/register/blob.cpp
@@ -98,17 +98,4 @@ void Blob::CopyFrom(DeviceCtx* device_ctx, const Blob* rhs) {
   }
 }
 
-namespace gdb {
-
-const Blob* CpuBlobCopyFromGpuBlobPtr(uint64_t gpu_blob_ptr) {
-  Blob* gpu_blob = reinterpret_cast<Blob*>(gpu_blob_ptr);
-  char* cpu_body_ptr = reinterpret_cast<char*>(malloc(gpu_blob->ByteSizeOfDataContentField()));
-  cudaMemcpy(cpu_body_ptr, gpu_blob->dptr(), gpu_blob->ByteSizeOfDataContentField(),
-             cudaMemcpyDeviceToHost);
-  return new Blob(const_cast<Regst*>(gpu_blob->regst()), gpu_blob->blob_desc_ptr(),
-                  reinterpret_cast<char*>(gpu_blob->mut_header_ptr()), cpu_body_ptr);
-}
-
-}  // namespace gdb
-
 }  // namespace oneflow
diff --git a/oneflow/core/register/blob.h b/oneflow/core/register/blob.h
index c7ec70dd57600f1325558d93c9d2f950d937e6d1..d6cf1e8e6b6b1f6cc494863233764165f9545cbe 100644
--- a/oneflow/core/register/blob.h
+++ b/oneflow/core/register/blob.h
@@ -75,7 +75,6 @@ class Blob final {
   void set_max_col_id(int32_t val);
   bool IsColValid() const { return col_id() <= max_col_id(); }
   const MemoryCase& mem_case() const;
-  const Regst* regst() const { return regst_; }
 
  private:
   template<typename T>