Abstract: The electrophoresis and salt spray properties of MAG welding and CMT welding carbon steel joints with different welding wires were studied, and the effect of chemical composition of welding wire on weld corrosion resistance was analyzed. The mechanical properties of welded joints were compared to ensure that the quality of welded joints meets the quality standards of white body welds, and the anti-corrosion properties of automobile body appearance welds are improved. The results show that silicate slag on weld surface is the main cause of deterioration of electrophoretic and salt spray properties. The comprehensive performance of mechanical and anti-corrosion of CMT brazing joints welded by silicon bronze welding wire is better than that of the MAG joints welded by carbon steel welding wires. Thus, the welding wire of silicon bronze can replace the carbon steel welding wire for the welding of joints on the exterior surface of car body.