Laser welding technology has been widely applied in foreign car manufacturing. According to statistics, in 2000, there were over 100 laser welding production lines for cutting blank plates worldwide, with an annual production of 70 million pieces of car component welding blank plates, and it continues to grow at a relatively high rate. Domestic production of imported car models also adopts some cutting blank structures. Japan uses CO2 laser welding instead of flash butt welding for the connection of rolled steel coils in the steel industry. In the research of ultra-thin plate welding, such as foil with a thickness of less than 100 microns, fusion welding cannot be achieved, but YAG laser welding with a special output power waveform has been successful, demonstrating the broad prospects of laser welding. Japan has also successfully developed YAG laser welding for the first time in the world for the repair of steam generator tubes in nuclear reactors, and has also carried out gear laser welding technology in China.