Abstract: The character of keyhole model in laser welding is deeply analyzed.Based on that,the appropriate models of heat source are applied.The quasi-steady and transient temperature fields with a moving line heat source and a gauss heat source are studied.By using MATLAB and ANSYS,laser welding temperature fields are calculated and simulated separately.Comparison between the two results has showed the precision of the models.Finally,the comparison between the experiment results and the simulated results has also validated the applicability of the keyhole model and gauss heat source model.