An epoxy/modified silicon dioxide corrosion resistant nanocomposite material and a preparation method thereof are disclosed. The method includes the steps of: dispersing TS(TEOS-SiO2) or APTES/TEOS-SiO2 (TAS) in solvent so as to form TS solution or TAS solution; adding triphenylolmethane triglycidyl ether and 1,4-butanediol diglycidyl ether into the TS solution or TAS solution to produce glycidyl ether/TS solution or glycidyl ether/TAS solution. Add a curing agent into the glycidyl ether/TS solution or glycidyl ether/TAS solution to generate epoxy/TS solution or epoxy/TAS solution. After curing, obtain epoxy/modified silicon dioxide nanocomposite corrosion resistant material. The material is applied to optoelectronics or other fields for corrosion prevention.