diff --git a/source/Makefile.Objects b/source/Makefile.Objects
index 8439558806..eb5844d9c7 100644
--- a/source/Makefile.Objects
+++ b/source/Makefile.Objects
@@ -249,7 +249,6 @@ OBJS_ESOLVER=esolver.o\
 
 OBJS_ESOLVER_LCAO=esolver_ks_lcao.o\
       esolver_ks_lcao_tddft.o\
-      dpks_cal_e_delta_band.o\
       lcao_before_scf.o\
       esolver_gets.o\
       lcao_others.o\
diff --git a/source/module_esolver/CMakeLists.txt b/source/module_esolver/CMakeLists.txt
index 0f8eba8c8b..395350f1d5 100644
--- a/source/module_esolver/CMakeLists.txt
+++ b/source/module_esolver/CMakeLists.txt
@@ -16,7 +16,6 @@ if(ENABLE_LCAO)
   list(APPEND objects
       esolver_ks_lcao.cpp
       esolver_ks_lcao_tddft.cpp
-      dpks_cal_e_delta_band.cpp
       lcao_before_scf.cpp
       esolver_gets.cpp
       lcao_others.cpp
diff --git a/source/module_esolver/dpks_cal_e_delta_band.cpp b/source/module_esolver/dpks_cal_e_delta_band.cpp
deleted file mode 100644
index d2d0cf45a0..0000000000
--- a/source/module_esolver/dpks_cal_e_delta_band.cpp
+++ /dev/null
@@ -1,69 +0,0 @@
-#include "esolver_ks_lcao.h"
-#ifdef __DEEPKS
-#include "module_hamilt_lcao/module_deepks/LCAO_deepks.h"
-#include "module_hamilt_pw/hamilt_pwdft/global.h"
-#endif
-
-namespace ModuleESolver
-{
-
-    using namespace std;
-
-#ifdef __DEEPKS
-    template<>
-    void ESolver_KS_LCAO<double, double>::dpks_cal_e_delta_band(
-       const vector<vector<double>>& dm)const
-    {
-        GlobalC::ld.cal_e_delta_band(dm);
-    }
-
-
-    template<>
-    void ESolver_KS_LCAO<complex<double>, double>::dpks_cal_e_delta_band(
-        const vector<vector<complex<double>>>& dm)const
-    {
-        GlobalC::ld.cal_e_delta_band_k(dm, this->kv.get_nks());
-    }
-
-
-    template<>
-    void ESolver_KS_LCAO<complex<double>, complex<double>>::dpks_cal_e_delta_band(
-        const vector<vector<complex<double>>>& dm)const
-    {
-        GlobalC::ld.cal_e_delta_band_k(dm, this->kv.get_nks());
-    }
-
-
-    template<>
-    void ESolver_KS_LCAO<double, double>::dpks_cal_projected_DM(
-        const elecstate::DensityMatrix<double, double>* dm)const
-    {
-        GlobalC::ld.cal_projected_DM(dm,
-            GlobalC::ucell,
-            orb_,
-            GlobalC::GridD);
-    }
-
-
-    template<>
-    void ESolver_KS_LCAO<complex<double>, double>::dpks_cal_projected_DM(
-          const elecstate::DensityMatrix<complex<double>, double>* dm)const
-    {
-        GlobalC::ld.cal_projected_DM_k(dm,
-            GlobalC::ucell,
-            orb_,
-            GlobalC::GridD);
-    }
-
-
-    template<>
-    void ESolver_KS_LCAO<complex<double>, complex<double>>::dpks_cal_projected_DM(
-          const elecstate::DensityMatrix<complex<double>, double>* dm)const
-    {
-        GlobalC::ld.cal_projected_DM_k(dm,
-            GlobalC::ucell,
-            orb_,
-            GlobalC::GridD);
-    }
-#endif
-}
diff --git a/source/module_esolver/esolver_ks_lcao.cpp b/source/module_esolver/esolver_ks_lcao.cpp
index 84e005902b..371218361d 100644
--- a/source/module_esolver/esolver_ks_lcao.cpp
+++ b/source/module_esolver/esolver_ks_lcao.cpp
@@ -879,7 +879,7 @@ void ESolver_KS_LCAO<TK, TR>::iter_finish(const int istep, int& iter)
         const std::vector<std::vector<TK>>& dm
             = dynamic_cast<const elecstate::ElecStateLCAO<TK>*>(this->pelec)->get_DM()->get_DMK_vector();
 
-        this->dpks_cal_e_delta_band(dm);
+        GlobalC::ld.dpks_cal_e_delta_band(dm, this->kv.get_nks());
     }
 #endif
 
diff --git a/source/module_esolver/esolver_ks_lcao.h b/source/module_esolver/esolver_ks_lcao.h
index a52160095c..95cdd9f77f 100644
--- a/source/module_esolver/esolver_ks_lcao.h
+++ b/source/module_esolver/esolver_ks_lcao.h
@@ -92,13 +92,6 @@ class ESolver_KS_LCAO : public ESolver_KS<TK> {
     std::shared_ptr<Exx_LRI<std::complex<double>>> exx_lri_complex = nullptr;
 #endif
 
-  private:
-#ifdef __DEEPKS
-    void dpks_cal_e_delta_band(const std::vector<std::vector<TK>>& dm) const;
-
-    void dpks_cal_projected_DM(
-        const elecstate::DensityMatrix<TK, double>* dm) const;
-#endif
     friend class LR::ESolver_LR<double, double>;
     friend class LR::ESolver_LR<std::complex<double>, double>;
 };
diff --git a/source/module_hamilt_lcao/module_deepks/LCAO_deepks.cpp b/source/module_hamilt_lcao/module_deepks/LCAO_deepks.cpp
index ddf0723d83..0c6701e83d 100644
--- a/source/module_hamilt_lcao/module_deepks/LCAO_deepks.cpp
+++ b/source/module_hamilt_lcao/module_deepks/LCAO_deepks.cpp
@@ -482,4 +482,14 @@ void LCAO_Deepks::del_v_delta_pdm_shell(const int nks,const int nlocal)
     return;
 }
 
+void LCAO_Deepks::dpks_cal_e_delta_band(const std::vector<std::vector<double>>& dm, const int nks)
+{
+    this->cal_e_delta_band(dm);
+}
+
+void LCAO_Deepks::dpks_cal_e_delta_band(const std::vector<std::vector<std::complex<double>>>& dm, const int nks)
+{
+    this->cal_e_delta_band_k(dm, nks);
+}
+
 #endif
diff --git a/source/module_hamilt_lcao/module_deepks/LCAO_deepks.h b/source/module_hamilt_lcao/module_deepks/LCAO_deepks.h
index bd11deef26..cd8d899a65 100644
--- a/source/module_hamilt_lcao/module_deepks/LCAO_deepks.h
+++ b/source/module_hamilt_lcao/module_deepks/LCAO_deepks.h
@@ -382,6 +382,10 @@ class LCAO_Deepks
     void cal_e_delta_band_k(const std::vector<std::vector<std::complex<double>>>& dm /**<[in] density matrix*/,
                             const int nks);
 
+    //! a temporary interface for cal_e_delta_band and cal_e_delta_band_k
+    void dpks_cal_e_delta_band(const std::vector<std::vector<double>>& dm, const int nks);
+    void dpks_cal_e_delta_band(const std::vector<std::vector<std::complex<double>>>& dm, const int nks);
+
     //-------------------
     // LCAO_deepks_odelta.cpp
     //-------------------