Automotive sheet metal can repair the interface iron plate by welding, shaping, correcting and patching. In the process of repairing automotive sheet metal, welding is one of the common methods, which can repair the damage on the interface iron plate. Welding can connect two interface iron plates together through the action of thermal energy to form a stable combination. Appropriate welding equipment and materials should be used in the repair process, and the operation should be carried out in strict accordance with the corresponding welding specifications and processes to ensure the quality and safety of repair.