The wheel outer rim groove polishing device includes three major systems, which are a wheel rotation system which is used for positioning, clamping and rotating of a wheel, thereby polishing all grooves in the circumferential direction of the wheel, a left polishing system for reciprocally polishing groove tool grains in the longitudinal direction, and a right polishing system for reciprocally polishing groove tool grains in the transverse direction; and three systems cooperate with each other and are combined orderly to jointly complete the polishing of tool grains on the wheel outer rim grooves. The present disclosure can meet the requirements for polishing the tool grains on the wheel outer rim grooves. Compared with artificial polishing, the device improves the polishing effect, improves the work efficiency, and reduces the risk of rim deformation. The device has the characteristics of high efficiency, practicality, easy manufacture, flexible operation and the like.