Abstract: Optical remote sensing is an important means for spaceborne remote sensing, and optical films also have been applied widely in temperature control and energy supply systems of satellite. Their performance in space environment plays an important role for satellite operation in orbit, especially for satellite life and safety. This paper gives the physical mechanisms of the effects of solar UV radiation on optical films, and analyses its rule of this effects. In addition, the influences of atom oxygen erosion, energetic particles and electrostatic charging on the optical films degradation induced by under solar UV irradiation have been analyzed. The experimental results about the effects of solar UV radiation on space-based optical system coatings are also reviewed. Finally the suggestions for contamination protection are provided.