The application and development trend of laser welding technologies for car body-in-white is analyzed in details,and the optical characteristics of laser welding light source and the absorption characteristics of different materials are studied. Combining with car body product characteristics and the application of new materials such as high-strength aluminum alloy,the relative principles,technical characteristics and application of laser welding technologies are introduced and compared,including laser fusion welding technology,laser fusion wire filler welding technology,laser brazing technology and laser +MIG hybrid welding technology. Based on the different product structures and material characteristics,the reasonable solutions of laser welding technology are provided from above mentioned laser welding methods. Considering the development of car body-in-white in the future and the requirements of higher quality welding body,the laser welding technology with three spots and the laser spot welding technology are proposed,and their welding principles,technical characteristics and technological characteristics are also analyzed and introduced. This has certain application value and guiding significance for future automobile body welding solutions.