Application of laser is increasing in spacecraft now, but laser systems in space already have the sudden phenomenon of failure. The optics performances composed of coatings and substrates such as crystal and glass are important elements for laser generation and output. The changes of damage performances will affect the stability, lifetime and beam quality of laser system in space. Space effects of optics have become an urgent problem to research and discuss. We summarize the variation trend, damage mechanism and some improvement measures for optics in different conditions of vacuum, temperature, contamination, solar ultraviolet radiation and proton radiation, respectively. The conclusions will be helpful to the future laser applications and research in space.