Abstract: The thermal field of metal plates in flows under laser irradiation has been computed. The flow was governed by the 3-D Reynolds averaged Navier-Stokes equations and the solid was governed by the energy equation. The k-ε turbulence model was used for turbulence simulation. Thus by using dynamic mesh model to simulate the flow’s “wash out” effect, the physical process of laser ablation was described commendably with fluid-solid coupling method. The results of thermal field and flow field show that the flow just cools the metal plates when the flow velocity and laser power are low. With the flow velocity and laser power getting higher, the flow’s “wash out” effect becomes more important for the thermal field of metal plates.