Abstract: The structure of the welded joints of stainless steel and aluminum alloy were studied in this paper. The advantages and disadvantages of butt joints and lap joints were compared,and the most optimal solution was obtained. The results show that TIG butt welded joints are superior to that by the electric resistance welding. The aluminum crown can not be close to the weld end. The crown structure which was close to the end of the weld made the local rigidity and higher residual stress,which easily made the longitudinal crack.