A hybrid power supply device of an air-conditioner for supplying multiple electric power sources to a DC rail of an inverter of a DC brushless motor of the air-conditioner to drive the operation of the DC brushless motor is introduced. Two power sources may be selectively fed into the inverter of the DC brushless motor to provide hybrid power sources to the air-conditioner in a low cost simply by connecting the outputs of two one-way rectifiers. In addition, a voltage boost circuit is provided to program each source as the main power source and a backup power source. With the skillful arrangement of a simple circuit, the air-conditioner achieves the hybrid power supply effect with a multiple of controllable power sources.