Commonly used conservation materials for ion relics need to be improved, and development of such materials has very close relationship to the material sciences. Inorganic - organic hybrids are new products of material science that mingle the properties of organic and inorganic materials, leading to new functions. In this article an inorganic - organic hybrid material PMTES/Si02 ( or simply, MT) was prepared following basic rules for making sol - gels. In comparison tests, for example using salt mist accelerating corruption test and electrochemistry test, it has been shown that the hydrid is effective in lowering the corrosion rate of iron cultural relics. The preserving mechanism was explained.