Power supply system for metro vehicle

The invention discloses a power supply system for a metro vehicle. The power supply system comprises a main power supply and an auxiliary power supply, wherein the main power supply is connected with a load and is used for outputting a first driving voltage for driving the load; the auxiliary power supply comprises a voltage output port; the voltage output port is connected with the load and is used for outputting a second driving voltage for driving the load. The power supply system provided by the invention can continuously supply power to the load when the main power supply is in fault, so that the whole reliability of the power supply system is increased. The power supply system provided by the invention has a simple structure; a complex power supply system fault judging circuit is not required; the mounting is convenient; the cost of hardware is reduced; the failure rate of the system is reduced.