The present invention relates to a graphene-supported cerium oxide/rubber composite material and a preparation method thereof. The preparation method comprises the following steps: dropping cerium nitrate solution into graphene oxide solution while stirring; adding the mixed solution into a hydrothermal synthesis reaction kettle for calcination and cooling the reaction products to room temperature; washing the reaction products with ethanol and water and drying the reaction products to obtain graphene-supported cerium oxide; filling natural rubber/styrene-butadiene rubber with the graphene-supported cerium oxide, adding a vulcanization system, carrying out mixing to obtain a mixed rubber and carrying out vulcanizing on a curing press to obtain the graphite-supported cerium oxide/rubber composite material. The graphite-supported cerium oxide/rubber composite material can be used to make anti-radiation windshields of various shapes. In the invention, graphene and cerium oxide are compounded. The graphene is used as a carrier to improve electron transfer speed, and filling the natural rubber and styrene-butadiene rubber with the graphene can not only play the role of electromagnetic shielding but also prevent the natural rubber and styrene-butadiene rubber from aging. The graphene-supported cerium oxide/rubber composite material also has excellent mechanical properties, oxidation resistance and flexibility, and can be used to manufacture anti-radiation windshields to protect human health.