▎ 摘　　要

NOVELTY - Preparing magnetic graphene film with high electromagnetic wave absorption efficiency involves adding natural graphite powder into concentrated sulfuric acid; adding hydrogen peroxide (H2O2) to mixed product until gas is not generated to obtain suspension, under condition of temperature of 2-4degrees Celsius, then suspension free settling for 1-5 days to obtain precipitate; using pre-cooled diluted hydrogen chloride aqueous solution to wash precipitate for 4-8 times, then centrifuging at rotating speed of 4000-20000 revolutions/minute; washing metal ion precipitate with precooled deionized water for 2-10 times to remove metal ion; washing, diluting graphene oxide solution with deionized water to dilute concentrated graphene oxide liquid. USE - Method for preparing magnetic graphene film used for filtering, solution casting, spin coating, spraying and blade coating; used for magnetic separation of biological molecules, environmental pollution adsorption, catalytic and separation of water pollutant, doped polymer and constructing composite material, bearing nano medicine and establishing biological sensing and detecting method. ADVANTAGE - The method enables to prepare magnetic graphene film with high electromagnetic wave absorption efficiency, and high product purity and uniformity.