Abstract: The finite element simulation software Abaqus was used to study the friction stud welding process. A python script based on the Abaqus/stand algorithm has been designed, which can realize the functions of parameterization modeling, automatic remeshing, results mapping, thermal boundary automatic selection and so on. This can effectively solve the difficulty of convergence in calculation that is caused by the large scale nonlinear plastic deformation of materials. The simulation results of the plastic deformation of welded stud are basically consisted with and the experimental results effectively proving the validity of the finite element model. In addition, the analysis results of welding stress and temperature fields can explain the difference of the joint quality welded in the air and water with the same welding parameters. These works may have important guiding significance for the underwater friction stud welding application and welding process selection.