Abstract: In order to ensure the accuracy and the efficiency of the finite element simulation for welding, it was commonly applied by adopting a non-uniform mesh with transitional mesh of the weld joint. An automatic meshing method, which is suitable for finite element simulation of welding, was constructed by the use of progressing front method combined with a multi-level sweep stretching three-dimensional mesh generation method. The transition algorithm of weld joint was investigated based on welding FEM meshing characteristics and the corresponding image drawing program was developed by OpenGL source code. The calculation tests show that the multi-layer sweep structure can effectively ensure the transition towards two directions, and improve the mesh transition efficiency.