Abstract: A lot of computed methods which improve the efficiency of welding simulation were discussed, and base on line-gauss heat source model, a new method was presented which was called temperature function method.Compared with line-gauss heat source model, the control variable in temperature function method was changed from heat input to welding temperature, which led to more consistent between welding temperature field from simulation and experiment in width and thickness direction of model.This new high-efficiency simulation method was validated by a model of friction stir welding on Al alloy sheet in this paper.The simulation results show that not only the residual stress and distortion of the sheet from temperature function method is similar with that from moving heat source model method, which is validated by the experimental results, but also the efficiency of new method is significant increased, and achieves the time request of welding simulation in engineering application.