Abstract: GO@Fe₃O₄ composite nanoparticles are prepared by depositing Fe₃O₄ nanoparticles on the surface of graphene oxide (GO), and then the graphene solvent-free nanofluid is successfully prepared by grafting KH560-M2070 on the surface of the GO@Fe₃O₄ composite nanoparticles, whose dispersibility and compatibility are improved compared with other graphene-like materials in epoxy resin matrices. The graphene solvent-free nanofluids are characterized by TEM and XRD analysis methods, and the water resistance, acid and alkali resistance and thermal conductivity of the graphene fluid/epoxy coating are investigated.