Abstract: In engineering, the efficiency and accuracy of the welding heat source model are crucial considerations in the multi-layer and multi-pass welding simulation of large structural parts. In this study, a 316 LN stainless steel plate model was used in ABAQUS finite element calculation platform. The secondary development of Fortran subprogram and Python was used to fulfill the load of three welding heat source models, namely, double ellipsoidal heat source model（DEHS）,instantaneous heat source model（IHS） and moving body-element heat source（MBHS）. The accuracy of each heat source model was analyzed by examining the temperature field distribution, welding residual stress field and welding deformation.The advantages and disadvantages of the heat source model were assessed by considering the time spent on calculation. The simulation results indicate that while the IHS model has high calculation efficiency, its accuracy is poor, and it is not suitable for using alone in multi-layer and multi-pass welding simulation calculation. Compared with the DEHS model, the MBHS model has little difference on the temperature field and residual stress field, and the welding deformation difference is only7.2%, while the calculation time of the MBHS model is only 37.5% of that of the DEHS model. Therefore, the MBHS model is a suitable engineering heat source model, which can replace the DEHS model effectively.