The invention relates to the technical field of sewage purification, in particular to a graphene sewage purification material and a preparation method thereof. The graphene sewage purification material is prepared by the following four formulas: 1, 10-20 parts of graphene powder, 2-10 parts of polyacrylamide and 60-80 parts of polypropylene pyrrolidone; 2, one of a 100-800-mesh mesh fabric, a polyester mesh fabric, an acrylic fabric, a polypropylene fabric, a spandex fabric and a nylon fabric; 3, one or more of polyurethane sponge, polyvinyl alcohol sponge and melamine sponge, 100-150 parts of absolute ethyl alcohol, 5-10 parts of tetraethoxysilane, 2-5 parts of ammonia water and 2-3 parts of deionized water; and 4, a PVA aqueous solution or cross-linked PVA hydrogel are prepared by usingone or more of boric acid, borax and glutaraldehyde as a cross-linking agent. According to the invention, the prepared graphene sewage purification device is convenient to use, can perform large-scale oil-water separation, does not need to perform any post-treatment on a filter screen after separation, improves the analysis efficiency, and is long in service life.