diff --git a/source/module_hsolver/diago_bpcg.h b/source/module_hsolver/diago_bpcg.h
index 940a3aeb5a..71040960c3 100644
--- a/source/module_hsolver/diago_bpcg.h
+++ b/source/module_hsolver/diago_bpcg.h
@@ -24,7 +24,7 @@ namespace hsolver {
  * @tparam Device The device used for calculations (e.g., cpu or gpu).
  */
 template <typename T = std::complex<double>, typename Device = base_device::DEVICE_CPU>
-class DiagoBPCG
+class DiagoBPCG : public DiagH<T, Device>
 {
   private:
     // Note GetTypeReal<T>::type will 
@@ -56,15 +56,15 @@ class DiagoBPCG
     void init_iter(const psi::Psi<T, Device> &psi_in);
 
     /**
-     * @brief Diagonalize the Hamiltonian using the BPCG method.
+     * @brief Diagonalize the Hamiltonian using the CG method.
      *
-     * This function is called by the HsolverPW::solve() function.
+     * This function is an override function for the CG method. It is called by the HsolverPW::solve() function.
      *
      * @param phm_in A pointer to the hamilt::Hamilt object representing the Hamiltonian operator.
      * @param psi The input wavefunction psi matrix with [dim: n_basis x n_band, column major].
      * @param eigenvalue_in Pointer to the eigen array with [dim: n_band, column major].
      */
-    void diag(hamilt::Hamilt<T, Device> *phm_in, psi::Psi<T, Device> &psi, Real *eigenvalue_in);
+    void diag(hamilt::Hamilt<T, Device> *phm_in, psi::Psi<T, Device> &psi, Real *eigenvalue_in) override;
 
 
   private:
diff --git a/source/module_hsolver/diago_cg.h b/source/module_hsolver/diago_cg.h
index 1b64cfe4e8..bb106cd8c1 100644
--- a/source/module_hsolver/diago_cg.h
+++ b/source/module_hsolver/diago_cg.h
@@ -13,7 +13,7 @@
 namespace hsolver {
 
 template <typename T, typename Device = base_device::DEVICE_CPU>
-class DiagoCG final
+class DiagoCG final : public DiagH<T, Device>
 {
     // private: accessibility within class is private by default
     // Note GetTypeReal<T>::type will
@@ -36,11 +36,11 @@ class DiagoCG final
         const int& pw_diag_nmax,
         const int& nproc_in_pool);
     
-    ~DiagoCG();
+    ~DiagoCG() override;
 
     // virtual void init(){};
     // refactor hpsi_info
-    // this is the diag() function for CG method
+    // this is the override function diag() for CG method
     void diag(const Func& hpsi_func, const Func& spsi_func, ct::Tensor& psi, ct::Tensor& eigen, const ct::Tensor& prec = {});
 
   private:
diff --git a/source/module_hsolver/diago_dav_subspace.h b/source/module_hsolver/diago_dav_subspace.h
index 06d66aa8d2..8e26a08b45 100644
--- a/source/module_hsolver/diago_dav_subspace.h
+++ b/source/module_hsolver/diago_dav_subspace.h
@@ -11,7 +11,7 @@ namespace hsolver
 {
 
 template <typename T = std::complex<double>, typename Device = base_device::DEVICE_CPU>
-class Diago_DavSubspace
+class Diago_DavSubspace : public DiagH<T, Device>
 {
   private:
     // Note GetTypeReal<T>::type will
@@ -29,7 +29,7 @@ class Diago_DavSubspace
                       const bool& need_subspace_in,
                       const diag_comm_info& diag_comm_in);
 
-    ~Diago_DavSubspace();
+    virtual ~Diago_DavSubspace() override;
 
     // See diago_david.h for information on the HPsiFunc function type
     using HPsiFunc = std::function<void(T*, T*, const int, const int)>;
diff --git a/source/module_hsolver/diago_david.h b/source/module_hsolver/diago_david.h
index 576e36eed4..2a59eb2134 100644
--- a/source/module_hsolver/diago_david.h
+++ b/source/module_hsolver/diago_david.h
@@ -8,7 +8,7 @@ namespace hsolver
 {
 
 template <typename T = std::complex<double>, typename Device = base_device::DEVICE_CPU>
-class DiagoDavid
+class DiagoDavid : public DiagH<T, Device>
 {
   private:
     // Note GetTypeReal<T>::type will 
@@ -25,7 +25,7 @@ class DiagoDavid
                const bool use_paw_in,
                const diag_comm_info& diag_comm_in);
 
-     ~DiagoDavid();
+    virtual ~DiagoDavid() override;
 
 
     // declare type of matrix-blockvector functions.
diff --git a/source/module_hsolver/hsolver_pw.cpp b/source/module_hsolver/hsolver_pw.cpp
index 5ef07216c3..7e4bd3349d 100644
--- a/source/module_hsolver/hsolver_pw.cpp
+++ b/source/module_hsolver/hsolver_pw.cpp
@@ -228,7 +228,7 @@ void HSolverPW<T, Device>::solve(hamilt::Hamilt<T, Device>* pHamilt,
     const std::initializer_list<std::string> _methods = {"cg", "dav", "dav_subspace", "bpcg"};
     if (std::find(std::begin(_methods), std::end(_methods), this->method) == std::end(_methods))
     {
-        ModuleBase::WARNING_QUIT("HSolverPW::solve", "This type of eigensolver is not supported!");
+        ModuleBase::WARNING_QUIT("HSolverPW::solve", "This method of DiagH is not supported!");
     }
 
     // prepare for the precondition of diagonalization
diff --git a/source/module_hsolver/test/test_hsolver.cpp b/source/module_hsolver/test/test_hsolver.cpp
index 4f5adb96ac..80ea102f97 100644
--- a/source/module_hsolver/test/test_hsolver.cpp
+++ b/source/module_hsolver/test/test_hsolver.cpp
@@ -83,4 +83,28 @@ class TestHSolver : public ::testing::Test
 
 // 	double test_diagethr_d = hs_d.set_diagethr(0.0, 0, 0, 0.0);
 // 	EXPECT_EQ(test_diagethr_d, 0.0);
-// }
\ No newline at end of file
+// }
+namespace hsolver
+{
+template <typename T, typename Device = base_device::DEVICE_CPU>
+class DiagH_mock : public DiagH<T, Device>
+{
+  private:
+    using Real = typename GetTypeReal<T>::type;
+
+  public:
+    DiagH_mock()
+    {
+    }
+    ~DiagH_mock()
+    {
+    }
+
+    void diag(hamilt::Hamilt<T, Device>* phm_in, psi::Psi<T, Device>& psi, Real* eigenvalue_in)
+    {
+        return;
+    }
+	};
+	template class DiagH_mock<std::complex<float>>;
+	template class DiagH_mock<std::complex<double>>;
+}
\ No newline at end of file