Abstract: The temperature field in electron beam welding of SiCp/101Al composite was numerically simulated by the ANSYS finite element analysis software,and the quantity of Al4C3 brittle phases in the joint was analyzed.The results show that the temperature distribution of electron beam welding could be accurately simulated by double ellipsoidal heat source model.The surface of welding pool showed circular distribution,and the inside showed conical distribution.Moreover,the quantity of Al4C3 brittle phase in welded joint could be greatly reduced by increasing the welding speed or decreasing the input power of electron beam when penetration joint was got.