A control device of a motor-driven 4WD vehicle includes: a 42V alternator 2 driven by an engine 1 to generate 3-phase AC electricity of 42 volts; a rectifying circuit 14 which rectifies the 3-phase AC electricity generated by the 42V alternator 2 and which supplies DC electricity after rectification to a motor M1 which drives rear wheels; an inverter 3 which lowers the electricity generated by the 42V alternator 2 into 14 volts and which converts the lowered AC electricity into DC electricity; and a 14V battery E1 which is supplied with the electricity obtained by the inverter 3 and which is charged. With this configuration, a generator can function as both a motor generator for charging the 14V battery E1 and a motor generator for generating driving electricity of the motor M1, and the configuration of the device can be simplified.