The application discloses a light and efficient through-shaft type wheel hub motor, which comprises a through-shaft, a wheel hub shell mounted on the through-shaft, a
machine core, a planetary reduction mechanism and a
clutch which are sequentially assembled along the through-shaft, the
clutch comprises an outer ring and an inner ring, the inner ring is fixed on the through-shaft, the planetary reduction mechanism comprises a sun gear arranged on an output end of the
machine core and a plurality of planetary gears, the planetary gears are arranged on planetary shafts, the planetary shafts are fixed to the outer ring of the
clutch, the sun gear is in transmission connection with a ring gear fixed to the inner side of the wheel hub shell through the planetary gears, and the planetary gears are double planetary gears, the double planetary gears comprise coaxially arranged large and small gears, the large gear is a plastic gear and is in mesh with the sun gear, the small gear is a
metal gear and is in mesh with the ring gear, and an extension shaft sleeve is integrally arranged at the center of the small gear to fix the large gear. The through-shaft type wheel hub motor can ensure high output power and good internal structural strength under the premise of reducing weight, and the volume is further reduced.