Abstract: Temperature field of laser welding stainless steel 304 was dynamically simulated with finite element analysis software-ANSYS.Effects of temperature correlation of the physical parameters of material,latent hear of fusion,convection and radiation on the temperature field of laser welding were analyzed.In view of the characters of laser welding,a heat source combined the body loads were designed.Considering the high non-linear of the solution and the small focal diameter,a serial of measures were adopted,such as modeling with pyramid,stepped loading and solution.In the load history,an over-measure control method was taken to ensure the precision of nodal selection.It was shown that the simulation results of weld shape were in accordance with the experimental results,the isotherms looked like ellipse and were dense at the head of the moving heat source.And the temperature gradient was high at the head of the heat source.But at the end of the moving heat source the isotherms were sparse and the temperature gradient was low.Temperature near the surface of the weld pool was the highest,and up to about 13 332℃.