Abstract: The thermal field of metal plates in air flows under laser irradiation was computed. The numerical simulation was based on fluid-solid coupling method. The two phase flow model was used to simulate the scouring effect. It employed an implicit finite-volume, Gauss-Seidel scheme for solving the Reynolds averaged Navier-Stokes equations and solid energy equation in a coupled manner. The k- turbulence model was used for turbulence simulation. The physical process of laser ablation was described commendably with this method. The results of the thermal field and morphologies at different flow speed are presented in this paper. The results of two phase flow model and dynamic mesh model are compared and discussed. The results indicate that although the two models have the same thermal field results, the two phase flow model is more fit for physical process of laser ablation characterization.