The invention provides an oil-saving vehicle-protecting graphene composite material, and belongs to the technical field of energy conservation. The composite material comprises a matrix and a graphenematerial which is dispersed in the matrix, wherein the matrix is mineral powder, the graphene material is loaded with negative ion bodies, and the graphene composite material is of a block-shaped porous structure with a pore diameter of less than 10 microns. The preparation method of the graphene composite material comprises the steps: mixing at least one binder with at least one additive, graphene powder and the mineral powder, then performing compression molding, and performing fixed dispersion on the graphene material in the matrix of the mineral powder. Through the graphene composite material, negative ions can be provided so as to improve the fuel combustion efficiency and power output, the fuel consumption amount per 100 kilometers is reduced after use, deposited carbon in automobile parts is reduced, emission of exhaust gas is reduced, and odor of the exhaust gas is thinned; and through the preparation method, agglomeration of graphene can be avoided, high infrared emissivity can be maintained, the amount of released negative ions by the product can be increased, the time of a release reaction is shortened, the surface roughness and friction coefficient of the product can be reduced, the wear resistance of the product can be enhanced, and the production cost is reduced.