The present invention discloses a high-precision rear-axle reduction gearbox for a scooter, comprising a box body, wherein an inner chamber is formed within the box body, and an opening for communicating the inner chamber with the outside is formed on the box body; a cover for sealing the opening is fitted at the opening of the box body; output shaft hole for allowing an output shaft to pass therethrough and an input shaft hole for allowing an input shaft to pass therethrough are formed on the box body; a driving motor is provided outside the box body; a differential component is provided within the inner chamber of the box body; a driving motor output shaft of the driving motor is linked to an input shaft, and the input shaft is linked to an output shaft via the differential component; and, the opening is relatively located on a radial outer side of the output shaft, and the opening is deviated from the output shaft holes and the input shaft hole.