For some extreme environment, such as vibration and shock during rocket launching or ultralow temperature in tank of cryogenic propellant, some key technology of the optical measurement device used in liquid oxygen tank of carrier rocket have been researched. In order to obtain a light-weight, high-stiffness and large-heat resistance main board structure for optical measurement device, a thermo-mechanical topology optimization technique is introduced into the main board structure design of optical measurement device for improving the designing quality. Compared with that before the optimization the main board structure reduces weight loses 46.8 percent with the first-order natural frequency above 420 Hz. The numerical results indicate that after adopting the topologic optimization design method, not only the design course is shortened, but also the main board structure weight is effectively reduced, heat resistance is effectively increased and the capability of the main board structure is enhanced. The extreme temperature test results show that the method is effective. © 2019 SPIE.