A method for preparing a graphene oxide grafting surface modification carbon fiber relates to a carbon fiber modification method, and is used for solving the technical problems that the existing carbon fiber has low surface activity, reduced surface tension and poor wettability with a resin matrix, and the interlaminar shear strength of a composite material is caused to reduce. The method comprises the steps as follows: 1, graphite oxidization; 2, separation of graphite oxide mother liquor; 3, functionalization of graphite oxide; 4, carbon fiber surface functionalization; and 5, carbon fiber surface graphite oxide treatment. The graphite oxide uniformly covers the carbon fiber surface, the roughness of the carbon fiber surface can be greatly improved, and accordingly, the interfacial properties of a carbon fiber reinforced composite material can be improved by an anchoring action. The interfacial shear strength of the surface grafting graphene oxide carbon fiber/carbon composite material which is prepared through graphene oxide grafting modification can be improved by 25% in comparison with that of the untreated surface grafting graphene oxide carbon fiber/carbon composite material.