The invention relates to a graphene composite material and a preparation method thereof. The graphene composite material provided by the invention is characterized in that a graphene material plate fixed on a metallic matrix serves as a carrier, and the elementary substance and/or a compound are compounded on the graphene surface. Meanwhile, the invention also discloses a method for preparing the graphene composite material. The graphene composite material prepared by the invention is opened between graphene sheets and is compounded with a chemical substance under the condition that a space body structure is formed, and the obtained material has high conductivity, high specific surface area and excellent performance of low electrical resistivity between the sheets, and can be widely applied to the fields of energy storage materials such as lithium ion batteries, super-capacitors, super lead carbon batteries, super nickel-carbon electrodes, solar energy and fuel cells, the field of heat dissipation materials, the field of environment-friendly adsorbing materials, the field of sea water desalination materials, the field of photoelectric sensor materials, the biological relevance field, the field of catalyst materials and the fields of conductive ink and coating materials.