The ball-screw-driven hoist was first used in line 1 ship lock of Liulaojian in north Jiangsu province. In order to reveal the law of motion and force and to provide the theory for further application and transformation, the motion and force of the ball-screw-driven hoist areanalyzed under conditions with frequency transformer and without frequency transformer. The result shows that when the nut runs 1.8 meters per minute at track, the force meets the design requirement of 300 kN whether or not we adopt the frequency transformer; when we adopt the frequency transformer, the motion of ship lock gate achieves“slow-fast-slow”, the motion of the lock gate is steadier, the force of gate opening and closing is larger, and the change rate of both the angular velocity and the force reaches about 33%.