Abstract: Efficient detection of ice cloud by the microwave detector in the terahertz band will greatly facilitate global and local climate research. However, due to the small internal space, the structure design of the imager is difficult. The layout of the electric machine is compact and the power consumption is large. The space environment and direct sunlight will cause the structural deformation of the antenna reflection surface, which affects the electrical performance of the load. The imager structure is designed in detail and its mechanical characteristics under various experimental conditions are verified by finite element software. Temperature data of space system is mapped to the model for thermal deformation calculation, then structural thermal deformation data is translated into Grasp system simulation. The effect of the thermal deformation on the electrical performance is evaluated based on coupling analysis. The result shows that the electrical performance meets the requirements.