The spreader is fully mechanical and does not have any electrical or hydraulic components. The crane has the function of mechanical automatic opening and closing rotation lock. The twist lock is provided with an opening and closing lock indicating device on the spreader mechanically controlled by pulling the wire rope. The worker who does not need the crane helps to hook/unhook, and the ground staff can judge the state of the turn-opening and unlocking by the direction of the pointer. The installation is simple and convenient, which greatly saves the conversion time from the lifting of the hook to the lifting of the container.