This paper studies the power supply system of urban rail Firstly， the development history and current situation of urban rail transit power supply system are discussed， and the necessary preparatory work for the design of urban rail transit power supply system is ， constructed the overall structure of the urban rail transit power supply system， established the general design principle， and the subsystem of urban rail transit power supply system design， the subsystem of the different design schemes are compared and Finally， MATLAB/Simulink was used to model and simulate the traction power supply system of the core subsystem， and the simulation results were
