diff --git a/source/module_hsolver/diagh.h b/source/module_hsolver/diagh.h
deleted file mode 100644
index 9ebc3f664f..0000000000
--- a/source/module_hsolver/diagh.h
+++ /dev/null
@@ -1,53 +0,0 @@
-#ifndef DIAGH_H
-#define DIAGH_H
-
-#include "module_base/macros.h"
-#include "module_hamilt_general/hamilt.h"
-#include "module_psi/psi.h"
-#include "module_hamilt_general/matrixblock.h"
-
-#include <string>
-
-#ifdef __MPI
-#include "mpi.h"
-#endif
-
-// template <typename T>
-// struct const_nums
-// {
-//     const_nums();
-//     T zero;
-//     T one;
-//     T neg_one;
-// };
-
-namespace hsolver
-{
-
-template <typename T, typename Device = base_device::DEVICE_CPU>
-class DiagH
-{
-  private:
-    using Real = typename GetTypeReal<T>::type;
-
-  public:
-    virtual ~DiagH(){};
-    // virtual void init()=0;
-    std::string method = "none";
-
-    virtual void diag(hamilt::Hamilt<T, Device>* phm_in, psi::Psi<T, Device>& psi, Real* eigenvalue_in)
-    {
-        ModuleBase::WARNING_QUIT("diagh", "diag method not implemented for the base class!");
-    };
-#ifdef __MPI
-    // diagnolization used in parallel-k case
-    virtual void diag_pool(hamilt::MatrixBlock<T>& h_mat, hamilt::MatrixBlock<T>& s_mat, psi::Psi<T>& psi, Real* eigenvalue_in, MPI_Comm& comm)
-    {
-        ModuleBase::WARNING_QUIT("diagh", "diag_pool method not implemented for the base class!");
-    };
-#endif
-};
-
-} // namespace hsolver
-
-#endif
\ No newline at end of file