The invention discloses a power supply for an EMU and a control method thereof. The power supply includes a DC power supply V dc , capacitance C 1 , capacitance C 2 , capacitance C 3 , capacitance C 4 , switch tube S 1 , switch tube S 2 , switch tube S 3 , switch tube S 4 , switch tube S 5 , diode d 1 , diode d 2 , filter LC and load resistance R; the control method is to ensure that only two switch tubes are turned on at the same time, and at the same time ensure the realization of the inverter process, multi-level output and voltage gain. The EMU power supply and its control method provided by the present invention have low common-mode electromagnetic interference, multi-level output and high-gain step-up and inversion capabilities, have small harmonic content, do not need an additional step-up circuit, are small in size, and low in cost , high efficiency characteristics.