Abstract: Diatomite is a kind of biomass sedimentary rock，which is widely used in chemical petroleum，building materials，biomedical health，environmental protection and other fields due to its characteristics of light weight，large specific surface area，super adsorption，noise abrasion resistance，heat resistance and corrosion resistance.It is similar in structure to silica and can be used as a substitute for silica to reinforce the rubber material.In this work，the diatomite produced by Heihe river in Heilongjiang province has been modified and the modification effect of different modifiers has been studied.The results show that the modification effect of Si69 is good.The modified diatomite/rubber composites were prepared by mechanical blending method.According to the mechanical properties test，the most suitable diatomite-reinforced rubber was fluorine rubber，EPDM rubber and acrylate rubber.SEM showed that the diatomite can be dispersed uniformly in the three kinds of rubber matrix with good compatibility and the composites have excellent mechanical properties.