The space optical remote sensor is developing in the direction of higher lightweight rate, but the traditional framing support is difficult to meet the requirement of the system. Bipod flexible support structure based on kinematics principle has good adaptability to mechanical and thermal environment, and has been more and more applied in mirror support of space optical remote sensor. In order to effectively remove the assembly stress, the Bipod flexible supporting structure is usually connected to mirror by optical glue. But there is inevitable shrinkage stress in the curing process of optical glue. In addition, the fluctuations of the ambient temperature and the thermal vacuum test could lead to additional force change, which will have an adverse impact on the shape of the mirror. In this paper, the influence of glue shrinkage on the surface shape of a Bipod flexible support secondary mirror assembly was analyzed. Aiming at the surface shape decline after vacuum deflation test, the combination of stress relief and hot immersion was used to effectively solve the surface shape decline problem, so as to provide technical support for the space environmental application of this kind of optical glue.