The welds of swivel arm positioning seat have some defects of incomplete fusion,undercut,unmanageable welding deformation and low production efficiency. Through analyzing the structural features of swivel arm positioning seat,the welding parameters and welding sequence are optimized. The results show that the optimized welding procedure effectively solves the welds quality problems,no need for repair and adjustment after welding. This method saves a lot of labor cost and production cost,and greatly improves the production efficiency.