Abstract: Based on dimensional analytic theory and non-dimensionalized thermo-mechanical coupling equations for high energy laser beam irradiation, this paper presents the similarity criterion and the scaling law for thermo-mechanical coupling effect induced by high energy laser beam under some reasonably approximation conditions. The similarity criterion and the scaling law are independent of material properties related to temperature. The finite element analysis models of full scale and scale down pressurized cylindrical shells irradiated by intense laser beam are established respectively. The numerical results show similarity between the full scale and scale down models. It is concluded that the coupling effect of the thermal-mechanics induced by intense laser beam meets similarity rules under re