The switching characteristics and energy consumption of SiC devices and Si devices were compared; the power losses of SiC devices and Si devices were compared according to the calculation of traction conditions of rail transit; for the application of high switching frequency, a series of tests including temperature rise, noise, power loss and efficiency were carried out. The test results showd that the traction inverter with SiC MOSFET can effectively reduce the harmonic loss of the motor, realize the energy saving and consumption reduction of the traction system, and reduce the motor noise in the middle and low speed sections.