Abstract: In order to reduce the influence of chips and cutting fluid on the application reliability of auxiliary measuring tools such as tool setter and ring gauge in the process of machine tool processing, a cylinder-driven automatic lid-opening protection device with simple structure and small space is proposed. The measuring tool is placed in the box, and the cylinder directly drives the cover body to rotate. When in use, the cover body rotates to open, and when not in use, the cover body rotates to close, so as to ensure the stable measurement of part accuracy in the process of machine tool processing, shorten the processing time, and reduce the manufacturing cost. Meanwhile, aiming at the problem of solving the position of the connection point between the cylinder and the cover body in the cylinder-driven automatic lid-opening protection device, a method to solve the problem of the cylinder-driven automatic lid-opening protection device is proposed by using the graphical method combined with the data discretization method. This method can directly read the optimal solution from the diagram, save the design time and achieve the optimal effect. The method is applied to the design process, motion simulation in 3D software, production and manufacturing, and finally applied to machine tools to solve practical problems.