Abstract: Since the complex protection configuration and malfunction problems of the blocking current selective trip protection adopted widely in urban rail transit 35 kV power supply system in China, a selective trip protection method is proposed. Through analyzing the performances of the new method in different fault conditions, its operational logic and working principle are expounded. The new protection method supports the information exchanges between different current selective trip protections based on digital communication protection technology, ensures the escalated acceleration through different types of permissive signals, also realizes the action time coordination between levels of protection adjacent to fault points, removes the fault selectively and quickly, solves the complex protection configuration and malfunction problems effectively.