The invention discloses a rail vehicle main circuit suitable for power supplying of a plurality of power supplies. The rail vehicle main circuit comprises a rectifier/chopper unit, an inverter unit and a bidirectional DC/DC conversion unit. The output end of the rectifier/chopper unit is connected with a traction motor through the inverter unit. The input end of the rectifier/chopper unit is connected with DC power supplies with different standards or AC power supplies with different standards. The input end of the inverter unit is connected with an on-vehicle energy storage unit through the bidirectional DC/DC conversion unit. When the input end of the rectifier/chopper unit is connected with the AC power supply, the rectifier/chopper unit is in a four-quadrant rectification state. When the input end of the rectifier/chopper unit is connected with the DC power supply, the rectifier/chopper unit is in a bidirectional DC/DC chopping state. The rail vehicle main circuit according to the invention has advantages of simple structure, stable output power supply, high suitability for different power supplies, etc.