The overload protection coupler comprises a hub, a first friction plate, a positioning ring and a locker, a pressure plate is sleeved on the hub, an adjusting nut is installed on the hub, the first friction plate is sleeved on the hub, a second friction plate is arranged between the first friction plate and the pressure plate, and the second friction plate is sleeved on the pressure plate. The first friction plate and the second friction plate are arranged in a semicircular mode, the positioning rings are connected with the first friction plate and the second friction plate, and the locker sleeves the positioning rings so that the first friction plate and the second friction plate can be installed on the hub. The two inner hexagonal screws are unscrewed, the two semicircular
bushing rings are separated, at the moment, the semicircular
bushing rings do not tightly hold the positioning ring, and after the first friction plate and the second friction plate lose the holding force of the semicircular
bushing rings, the first friction plate and the second friction plate which are spliced into a circle are separated in a semicircular mode and fall off from the hub along the axial space, and in the narrow space, the friction plate is separated from the hub. And the step of replacing the first friction plate and the second friction plate is simpler.