In order to overcome the shortcomings of the airborne photoelectric payloads(visible light cameras and infrared thermal imager), which has too short focal length and independent with each other, the visible light/infrared sharing aperture system key technology were studied. With visible light and medium wave infrared dual band sharing the primary and secondary mirror, the optical system focal lengths were 1 500 mm and 750 mm respectively for the visible light and infrared wave. By choosing appropriate optical material and the reasonable support method, the system reflector support component's static and dynamic models were designed, the structure form was optimized. The thermal-structural-optical integrated analysis method was used to guide, evaluate and optimize the opto-mechanical systems design process, improve the natural frequency of the structure and enhance thermal stability range. The fundamental frequency of the structure is greater than 200 Hz, the surface precision of the system reflector reaches PV of λ/10 and RMS of λ/40. The optical system modulation transfer function(MTF) reaches 0.38 under influence of deadweight and uniform temperature change of ±5 ℃. The results indicate that the proposed design can meet the requirements of high structure natural frequency, the gravity and thermal coupling deformation, vibration resistance, etc, and the system has good imaging quality.