Abstract: In order to effectively improve thermal insulation performance of filter components in subsequent optical system of spaceborne lidar, and ensure center wavelength tuning accuracy of F-P etalon which is core component by using hot-light characteristic of material, preliminary thermal structure for filter assembly is designed in this paper. Steady-state thermal analysis for initial structure of filter components is conducted by finite element software Ansys Workbench and heating power range is determined. Then key parameters of thermal structure are optimized by multi-objective based on sensitivity analysis and optimal value of each parameter is determined. Results show that maximum heating power is 7.05 W when temperature of F-P etalon reaches at 48℃, which saves power consumption of 11.3%. And maximum temperature difference of F-P etalon surface is reduced from 0.253℃ to 0.05℃, which meets requirements of design specifications.