The utility model discloses an urban rail transit vehicle DC freewheeling circuit and a traction inverter main circuit. The DC freewheeling circuit comprises a freewheeling branch circuit which is obtained through serially connecting a freewheeling diode and a freewheeling resistor; one end of the freewheeling branch circuit is successively connected with a short-circuit contactor, a main isolating switch and a high-speed circuit breaker, and is then connected with the positive output end of the an urban rail transit DC power supply, and the other end of the freewheeling branch circuit is connected with the negative output end of the DC power supply; the freewheeling branch circuit is parallelly connected with a serial-connected branch circuit of a reactor and a supporting capacitor in a traction inverter main circuit of the urban rail transit vehicle. The urban rail transit vehicle DC freewheeling circuit has a simple structure. The freewheeling circuit can release an inductive voltage generated at two ends of the reactor, thereby ensuring stable operation of the supporting capacitor of the traction inverter.