According to the task requirements on a light space remote-sensing camera of Jilin-1 satellite, a high-stability secondary mirror supporting structure was designed. For this purpose, integrated molding of the thin-walled cylinder and truss rod made of carbon fiber reinforced polymer composites was adopted as the design idea. And topology optimization, size optimization, and layer optimization were employed to design a secondary mirror supporting structure with high stability. The results of engineering analysis and tests show that the integrated carbon fiber secondary mirror supporting structure has favorable structural stability, with a mass of 1.3 kg. The on-orbit imaging performance of the space camera is great, which further verifies the reliability of the proposed supporting structure and the correctness of the design method.