The present disclosure relates to a high voltage cooling fan motor unit. For this purpose, the present disclosure includes a motor 100 located inside a high voltage cooling fan motor housing 102; an inverter PCB 200 located on the upper portion of the motor 100; a cover plate 300 for covering the upper surface of the motor housing 102, assembled in the state of facing the inverter PCB 200, and having a groove part 310 formed on the outside upper surface thereof; a cooling fin 400 provided on the outside of the cover plate 300 in the state of facing the groove part 310; and a power conversion unit 500 mounted on the lower surface of a heat sink 50 in the state of facing the inverter PCB 200 via the heat sink 50 mounted on the inside lower surface of the cover plate 300.