Abstract: Based on the superficial shape and geometry parameters of molten bath during laser brazing process,the heat distribution of surface bielliptic model was established to simulate the laser brazing process of beryllium ring.The results show that the simulated depth and width were consistent with experimental results and the model could simulate the laser brazing process of beryllium accurately.A comparison of the stress state change of internal and outside surface in heating and cooling process indicated that the welding solidification cracks appeared at the welded joint center and the large radial stress at welded joint center was the main factor of weld cracking.