Abstract: This paper investigated the slider in the center-pair crank-slider mechanism as the driving part, the relationship between the crank and the connecting rod was derived, and the conditions for realizing the accurate traverse were verified, the relationship between the crank and the connecting rod for generating the desired trajectory curve was obtained,along with the corresponding kinematic equations and trajectory curves. Meanwhile, the accuracy of the actual motion trajectory curve was verified by simulation analysis, and the motion trajectories of the points on the crank and connecting rod were analyzed to verify the condition that the precise wire on the connecting rod was a straight line, and relevant conclusions were drawn.Based on this theory, the lifting structure of medical linear accelerator cover plate was designed , successfully achieving the intended lifting function. Further simulations of the connecting rod structure showed that its strength met the design requirements. This study provides significant guidance for the application of crank-slider mechanisms in lifting structures.