Improving the temperature adaptability of optical mechanical structures is of great significance for space cameras to improve thermal control and stability of the system. Using a uniform material structure to eliminate thermal variation in the system, the optical and mechanical structure of a space camera in the visible light band is designed with aluminum alloy materials. Under actual working conditions, a uniform temperature of 20℃±15℃ was attained. Modulation transfer function (MTF) is greater than 0.3 at 71.4 lp/mm when the image changes in a different direction to gravity. The typical material matching schemes are comparatively analyzed. The stability of the all-aluminum structure under identical working conditions is far superior to that of structures using different materials, which verifies the effectiveness of the optical and mechanical structure of the unified material in terms of temperature adaptability.