An explosive strength training device is provided. The explosive strength training device includes a cable set, a power box, a resistance motor and a controller. The cable set includes a rubber belt and a movable pulley block connected with one end of the rubber belt, the movable pulley block has a first main pulley disposed opposite to the rubber belt, and allows the pulling force of the rubber belt to pass through the center of the first main pulley. Through the labor-saving structure of the first main pulley, the middle section of the power belt is wound on the upper side of the first main pulley and fixedly sleeved on the positioning rod with the fixed side to form a fulcrum.