Abstract: A heat source model suitable for laser heat-conduction brazing of Beryllium plates was developed according to the weld pool with a characteristic of small depth-width ratio.Three models were established respectively such as the compound heat source model that combined Gauss model with rotary body model in different proportions,the exponential-rotary parabolic body heat source model and the linear-rotary parabolic body heat source model.The thermal cycle curves of a point 2 mm ahead the start point and weld pool contours on cross section were predicted under same welding conditions by the three models,and welding experiments were performed to verify the models.The weld pool contours predicted by the two former models were compared in one experiment and the result showed they were.Meanwhile,it could not obtain a weld pool by using the linear-rotary parabolic body heat source model in current study.Results showed that the exponential-rotary parabolic body heat source model was the best one for its less parameter and good agreement with the experimental results.