The utility model relates to a double-commutator power supply system, which comprises a first commutator, a first equilibrium reactor and an inverter which are sequentially connected in series. The input end of the first commutator is connected with a first alternating current power supply, and the output end of the inverter is connected with an output isolation transformer. The double-commutator power supply system further comprises a second commutator and a second equilibrium reactor. The second commutator is connected with the second equilibrium reactor in series, the input end of the second commutator is connected with a second alternating current power supply, and the output end of the second equilibrium reactor is connected with the input end of the converter.