Research conclusions:The most advanced electrical technology，drive control technology，computer technology and network information technology are used to the train electrical traction system presented in this paper to achieve the goals of the electrical traction drive，electric braking，control，monitoring，information display and auxiliary power supply for ensuring the normal operation of the train． The train electrical traction system with full self intellectual property rights has worked successfully on the first － phase project of Kunming metro and the various functions and qualifications and the reliability of this train electrical traction system have been verified and checked comprehensively．The application shows this system can meet the technical requirements of the train of the first － phase project of the Kunming metro．