▎ 摘　　要

NOVELTY - Method for preparing graphene heat-dissipation composite material, involves (i) mixing graphite powder with nano-silicon dioxide, adding to a absolute ethanol solution, and dispersing and mixing using a high-speed dispersing machine to obtain a composite slurry, where the graphite powder is natural graphite powder or expanded graphite powder, (ii) placing composite slurry in a reaction kettle, heat-preserving at stirring speed of 300-500 rpm, 150-400 degrees C and pressure of 40-55 MPa for 0.5-2 hours, starting to release the pressure until the pressure is 5-30 MPa, and closing pressure valve to obtain a composite material with high temperature and high pressure reaction, (iii) taking out composite material that reacts under high temperature and high pressure, performing supercooling treatment, freeze-drying, and sheet forming to obtain a formed composite material, and (iv) placing formed composite material in a hot-pressing sintering furnace for heating and pressure sintering. USE - The method is used for preparing graphene heat-dissipation composite material.