Abstract: The temperature field of electron beam welding (EBW) in heat-resisting superalloy was simulated based on fusion zone boundary principle by finite-element method.The high temperature parameters of the material were estimated by linear interpolation method, equivalent replacement method etc.The combined model with Gauss surface heat source and cylindrical heat source was used according to both the nail-shaped weld and the deep penetration of electron beam welding.The simulation result was consistent with the real weld.The characteristics of temperature distribution of electron beam welding in the superalloy, and the heat cycle curves were showed in the results.The results offered information for optimizing the EBW process and studying on the residual stress.