Abstract: To ensure the imaging performance of the star coronagraph, the structural optimization design and analysis for the optics bench of Cool Planet Imaging Coronagraph (CPI-C) on China Space Station Telescope (CSST) was proposed. Firstly, the optimal structural design scheme of optics bench was obtained by numerical simulation. Then, the dynamics performance of the optimized design scheme was analyzed by numerical simulation. Finally, the experimental fixture was designed, and the mechanical properties of the optics bench were tested. The results show that the weight of optics bench is 8.6 kg, with a lightweight rate of 70.19% and the first order natural frequency of 322.46 Hz. The first order natural frequency of the coupled structure of the experimental fixture and optics bench is 269.63 Hz (>150 Hz). It indicates that the performance of the optics bench meets the design requirements and can be used for the CPI-C module.