The invention provides a graphene composite material used for fuel-saving ambulances, which belongs to the technical field of energy saving, and includes a matrix and a graphene material dispersed in the matrix, the matrix is mineral powder, and the graphene material is loaded with negative ions; the graphene The composite material is a massive porous structure with a pore size less than 10 microns. The preparation method comprises mixing at least one binder with at least one additive, graphene powder, and mineral powder, and then performing compression molding to immobilize and disperse the graphene material in the mineral powder matrix. The graphene composite material in the present invention can provide negative ions to improve fuel combustion efficiency and power output, reduce fuel consumption per 100 kilometers after use, reduce carbon deposits in auto parts, reduce waste gas emissions, and lighten tail gas odor; the preparation method can avoid graphene Agglomeration maintains high infrared radiation rate, increases product anion release, shortens release reaction time, reduces product surface roughness and friction coefficient, enhances product wear resistance, and has low production cost.