7N01 aluminum alloy is the key material of high-speed train body,which is often welded in different welding positions. In different welding positions,the adaptability of the joint to different positions is the key to determine the actual production process design. In this study,using the method of MIG and the current welding technology of high-speed train,the flat welding joint,overhead welding joint and vertical up welding joint of high-speed train structural material 7N01 were prepared,the macroscopic appearance of the joint was observed,the structure and performance of the welded joint under different positions were studied,and the influence of different welding positions on the joint performance was analyzed. The results show that the welding process at different welding positions can ensure the quality of the welded joint,and the tensile strength of the joint is the highest at PA position.