In view of the problems existing in the traditional strain detection methods, such as complex operation process, inability to realize real-time measurement and great influence by the environment, the digital image correlation (DIC) method was used to measure the strain values of copper/aluminum clad plate and its components during the tensile process, and the measured results were compared with those obtained by the stretching machine and the finite element simulation measurement. The results show that the strain curves of Cu plate, Al plate and Cu/Al clad plate obtained by DIC method and tensile test are very similar. The principal strain measured by DIC method has a high consistency with that simulated by finite element method, and the surface strain distribution is basically the same as the maximum principal strain, with a maximum difference of 0.442 % and a minimum of 0.008 %. The strain differences obtained by finite element simulation has a large variation with the maximum variation of 4.950 %, while that obtained by DIC method has a small variation with the maximum variation of 0.693 %. On this basis, the precision of DIC method and finite element method was studied by introducing strain differences, which verified the feasibility and superiority of the DIC method for the tensile strain detection of Cu/Al clad plate.