Abstract: In order to ensure the safety, reliability and stability of automatic phase transition of urban rail transit trains under AC power supply mode, and to reduce construction investment, according to the regulations of automatic phase transition of TB/T 3483-2017 CTCS-3 Train Control Equipment Technical Conditions, comprehensively considering the characteristics of small station intervals and small number of neutral zones along urban rail transit line routes and the implementation cost, the composition, principle and advantages of passive RFID (radio frequency identification) precise positioning technology are expounded, then the auto-passing neutral zone control system based on RFID precise positioning technology is studied from the aspects including system composition, working principle and equipment configuration. Passing neutral zone scheme under special working conditions is analyzed in detail. The scheme is suitable for the urban rail transit scenario of auto-passing neutral zone under AC power supply mode.