The application and research of laser welding technology for stainless steel car body of railway vehicle are discussed. First,the present situation and development history of laser welding for stainless steel car body are introduced. Then,starting from the welding principle,welding method and welding influence factors of laser welding technology,based on the laser welding technology of leading enterprises in railway vehicle industry,the laser welding is introduced. The advantages and disadvantages of laser welding technology for stainless steel car-body and its testing principle are illustrated from the analysis of the microstructure properties of material after welding by using the relevant technological test data.