Abstract: To popularize the laser welding technology in the industry，the characteristics of laser welding technology are introduced，the study and applications of laser welding in electronic packaging industry，such as manufacture of battery cell and packaging of microwave module，are summarized and the development of numerical simulation of laser welding process is introduced in this paper．Besides，the existing problems and the development trend of YAG laser welding technology are pointed out． The study shows that laser welding has been one of the most popular technology in electronic packaging industry and it will be used more and more widely with the development of laser welding system．