A method and apparatus for resetting a valve lift for use in an engine brake. A brake piston (160), and a hydraulic fluid passage (214) are arranged within a rocker arm (210) or a valve bridge (400) of an engine. A resetting valve arranged between the rocker arm (210) and the valve bridge (400) is driven by a change in the distance between the rocker arm (210) and the valve bridge (400). When the valve lift of an engine exhaust valve (300) reaches a maximum, a reset fluid passage (219) is opened, the hydraulic pressure within the hydraulic fluid passage is released, the brake piston (160) is reversed by one interval, the motion transmission between a cam (230) and the engine exhaust valve (300) is partially disengaged, and the valve lift of the engine exhaust valve (300) is reduced. Also, during a returning process of the valve lift of the engine exhaust valve (300) after reaching the maximum position, repositioning of the reset valve is used to maintain a supply of pressure within the hydraulic fluid passage, the brake piston (160) is allowed to be positioned at an extended position, and the motion transmission between the cam (230) and the engine exhaust valve (300) is resumed. The apparatus for resetting the valve lift can be integrated within an engine exhaust valve brake, and is structurally simple, convenient to install and to adjust, thereby improving safety and reliability.