Aiming at the protection of reflective main optical system for shipboard photoelectric tracking systems, an 1 m size optical window and its frame were designed, manufactured and tested. Firstly, the performance and strength of the window material were analyzed. According to the influence of the difference between internal and external pressures, the weight and the rotational inertia force on the window, the minimum thickness was determined. Then, the effects of deformation of optical window and frame on optical path difference and the environmental adaptability were studied base on the index requirements. Moreover, the aplanatic non-planar grinding method was used for machining and inspecting the optical window. Finally, an fused silica optical window with 1 032 mm in diameter, 80 mm in thickness and 1 010 mm in aperture diameter were successfully developed. The optical path difference is RMS=0.062 8λ@632.8 nm. The results proves that the optical window can provide an effective protection for main optical system of photoelectric tracking systems.