diff --git a/src/Matrix.cpp b/src/Matrix.cpp
index b5314b9..22199fe 100644
--- a/src/Matrix.cpp
+++ b/src/Matrix.cpp
@@ -1,5 +1,6 @@
 #include "Matrix.h"
 
+#include <cstddef>
 #include <mkl_cblas.h>
 #include <string>
 #include <cstring>
@@ -468,6 +469,9 @@ namespace Aurora {
     Matrix operator^( Matrix &&matrix,int times) {
         return operatorMxA(&vdPowI, times, std::forward<Matrix&&>(matrix));
     }
+
+    double Matrix::operator[](size_t index) const { return getData()[index];}
+
     void Matrix::printf() {
         if(isNull())
         {
diff --git a/src/Matrix.h b/src/Matrix.h
index 204cb73..449bb0f 100644
--- a/src/Matrix.h
+++ b/src/Matrix.h
@@ -169,6 +169,9 @@ namespace Aurora {
         friend Matrix operator==(double aScalar, const Matrix &matrix);
         Matrix operator==(const Matrix &matrix) const;
 
+        // sub
+        double operator[](size_t index) const;
+
 
         /**
          * 矩阵乘法