Provided is a cavitation pump unit. The cavitation pump unit includes a motor, a shaft axially mounted on a motor shaft, a plurality of impellers disposed at a predetermined distance along a circumferential surface of the shaft, and a housing surrounding the shaft and the plurality of impellers. The plurality of impellers includes cutter parts each of which protrudes to be inclined toward an inner surface of the housing in one direction, and cavitation grooves recessed inward in directions facing each other are defined in both side surfaces of each of the cutter parts.