The utility model discloses a hydraulic coupler detaching device which comprises a hydraulic coupler detaching working chamber for placing a hydraulic coupler, and a hydraulic cylinder arranged on a hydraulic cylinder fixing frame. A hydraulic cylinder piston rod is connected with the hydraulic coupler detaching working chamber which is provided with a hydraulic coupler detaching working chamber working face matched with a hydraulic coupler stress face. The hydraulic coupler detaching device has the advantages that when the detaching device is used for completing detaching and separating of the hydraulic coupler and a motor transmission shaft, operation is easy, centering performance is good, the hydraulic coupler stress face is even during detaching, under the situation that the hydraulic coupler and a motor are not damaged, quick separating of the hydraulic coupler and the motor is completed, and the hydraulic coupler detaching device is simple in structure, low in cost, safe and quick.