Abstract: As an easy-to-add and easy-to-implement external energy field, the magnetic field introduced into laser welding process can change the flow state of the current-carrying fluid, and affect the plasma morphology, droplet transfer, molten pool flow and keyhole behavior, thereby promoting and improving the weld structure, joint performance and welding process stability. The research results of magnetic field assisted laser welding in China and foreign countries were summarized, and the mechanism of the external magnetic field on laser welding and its influence on the characteristics of the laser welding process and the structure, defects and performance of the joint were summarized, and the future development of magnetic field assisted laser welding was prospected.