▎ 摘　　要

NOVELTY - The method comprises weighing 0.5-3 g of diamond powder and adding it to edible fish washing liquid, ultrasonically dispersing, centrifuging and washing multiple times, and then ultrasonically dispersing in deionized water to make a diamond powder dispersion, adding graphene oxide aqueous solution to diamond powder dispersion liquid, ultrasonically dispersing, making diamond powder-graphene oxide dispersion liquid, adding sodium borohydride aqueous solution dropwise during magnetic stirring of diamond powder-graphene oxide dispersion liquid, and continuing magnetic stirring for 1-3h, drying the clear liquid after suction filtration to obtain a diamond powder/graphene mixed powder after the dispersion liquid is centrifugally washed multiple times, and depositing different ratios of diamond powder/graphene mixed powder on a steel substrate by electrodeposition to obtain a graphene/diamond composite film, where the edible fish washing liquid is sulfuric acid and hydrogen peroxide. USE - The method is useful for preparing graphene/diamond composite film. ADVANTAGE - The method: is simple and easy to operate; and pre-treats the diamond powder with edible fish washing liquid to obtain graphene/diamond composite films with different mass ratios.