Abstract: By stainless steel welding wire with different Si element content, the weld forming, microstructure and performance after high-speed welding has been organized for research purposes, with the GMAW welding method,by analysis means of SEM, XRD diffraction pattern, mechanical properties such as stretching and the micro hardness testing, to further study of Si elements in the weld internal space distribution, and its influnce rule on microstructure,mechanical properties when forming after welding. The results show that the specific content of Si element in the welding wire can not only increase the metal fluidity in the weld pool, but also improve the stability of the welding process and the weld forming after welding. At the same time, the welding speed can be greatly increased to 120 cm/min; As a result of the existence of element Si, the joint organization after GMAW high-speed welding mainly austenite and δferrite, weld organization optimized.In XRD diffraction pattern after welding, martensite and cementite exists in the joint organization, micro hardness increased, tensile properties are basic flat, and apparent necking have appeared in front of the tensile fracture, plasticity and tensile strength are good.