▎ 摘　　要

NOVELTY - Preparing graphene comprises dipping a substrate material in ethanol solution with certain concentration for 10 minutes to 2 hours, drying a surface of the material attached with a layer of biomass derived carbon in a middle phase of a thin film, performing heat treatment of the material to form a graphene film on a surface of the material under protection of atmosphere containing hydrogen, again dipping the material in alcohol solvent by ultrasonic dispersion, and separating the film from the material provided with surface atoms of the substrate forming a graphite polyvinyl alcohol sol-gel. USE - The method is useful for preparing graphene (claimed), which is useful in a solar battery, an electronic device and a sensor. ADVANTAGE - The method enables simple preparation of graphene with low energy consumption and low cost biomass derived carbon raw material.