Ground direct-current power supply switching box for helicopter

The utility model discloses a ground direct-current power supply switching box for a helicopter, and the switching box comprises a first socket which is connected with a ground power supply; the second socket is used for being connected with a helicopter; the direct current contactor is used for connecting the first socket and the second socket when being powered on and disconnecting the electric connection between the first socket and the second socket when being powered off; the voltmeter is used for detecting the voltage output by the first socket and outputting a first signal to the second relay when the voltage is out of a preset range; the first relay is used for outputting a second signal to the second relay when the current output by the first socket is greater than a preset value; and the second relay is used for disconnecting the electric connection between the first socket and the direct current contactor when the first signal or the second signal is received. The ground direct-current power supply