Method for preparing graphene composite material

The invention relates to a method for preparing a graphene composite material. The method comprises the following steps of: suspending: adding a graphene sheet into a solvent to obtain a graphite suspension, wherein the graphene sheet is made of multilayer stacked grapheme materials; stripping: stripping the graphene sheet in the graphite suspension into a plurality of single-layer grapheme materials mechanically to obtain a graphene suspension; separating the single-layer grapheme materials in the graphene suspension from a small part of unstripped graphene sheet, and removing the small part of unstripped graphene sheet to obtain a graphene dispersion; and adding an active substance: adding the active substance into the graphene dispersion, and combining the active substance with the single-layer graphemes in the graphene dispersion to obtain a graphene composite material dispersion.