A motor oil pump assembly includes: a motor component; an oil pump component, where the oil pump component is supported on an end cover of the motor component; an inner sound insulation enclosure, where the inner sound insulation enclosure encloses the oil pump component, and the inner sound insulation enclosure and the oil pump component define an inner sound insulation cavity filled with low-pressure oil; and a pre-tightening buffering component, where the pre-tightening buffering component is pressed between an upper end cover of the oil pump component and the inner sound insulation enclosure, and the pre-tightening buffering component is in communication with a high-pressure cavity of the oil pump component.