The structure design demands of lift platform used in certain environment are studied based on the interface dimension of the bottom load optomechanical module of amplifier. The calculation model of the lift platform is designed based on the equal strength beam theory. The stiffness formula of variable cross-section platform structure is deduced, and the main structural parameters of the lift platform are calculated based on this stiffness formula. The 3D model of the lift platform is built based on ANSYS software and the structural mechanics analysis of the lift platform is carried out, then the rationality of the theoretical design parameters is verified by the analysis results. On the premise of improving the safety factor, the 3D model of the platform is reconstructed with ANSYS software and the stiffness redundancy analysis of the platform is carried out. For the sake of getting the lightest quality of the lift platform, the main structural parameters of the lift platform are optimized by using the global optimization tool of the ANSYS software. The optimization results are applied to the production of a vertical lifting mechanism sample of a system.