Abstract: In order to study the deformation law and control technology of the large-scale tubesheet group seam laser welding, we establish a 12 mm thick Q235 porous tubesheet group seam simulation piece considering the high temperature and mechanical performance parameters of the material, and design 5 kinds of symmetric and asymmetric welding paths. The welding process simulation software InteWeld is adopted to simulate and study the influences of different welding paths on the welding deformation. The results show that when the path is welding from top to bottom sequentially, the average and axial deformations are the smallest.