The laser welding is a high-efficiency joining technique with high energy density, narrow heat affected zone and small workpiece deformation. However, problems still exist in laser welding, such as high cooling speed, cracks, pores, etc. Spatters and pores were effectively inhibited by adding suitable gas or using oscillating laser. The joint defect was reduced and the welding process stability was effectively improved by using arc assisted laser welding. Laser welding assisted by ultrasonic, magnetic and electric fields can improve joint performance by refining grain, reducing element segregation and crack sensitivity. The review on laser welding was summarized from three perspectives, namely process optimization, auxiliary heat source and auxiliary energy field. Finally, problems existing in the research of energy field assisted laser welding were analyzed and its development prospect was forecasted.