▎ 摘　　要

NOVELTY - Preparation of ultra-fine diamond-graphene composite material comprises mixing superfine diamond and graphene in solvent to form dispersion, where the particle diameter of superfine diamond is 5 nm to 5 mu m, the mass ratio of superfine diamond and graphene is 0.05:5, the solvent is water, or ethanol and/or acetone, and the concentration of dispersed liquid is 0.1-10 wt.%; filtering to obtain superfine diamond-graphene mixed film, where the thickness of film is 0.1 mu m to 1 mm; and subjecting to vacuum heat treatment at 800-1200 degrees C for 0.5-2 hours to obtain composite material. USE - Method for preparing ultra-fine diamond-graphene composite material used for ultrafine abrasive tool, super capacitor, field emission display and semiconductor device (claimed). ADVANTAGE - The composite material has stable performance.