Abstract: Heat transfer and fluid flow simulations in the weld pool are an important aspect in welding simulation.At present most of heat transfer and fluid flow model in the weld pool were mainly based on the Navier Strodes equation.In this paper,some progress attained in recent years on heat transfer and fluid flow in weld pool was summarized,then generalized the factors that influenced heat transfer and fluid flow greatly.Finally,the developing direction of heat transfer and fluid flow simulation in weld pool is presented.