▎ 摘　　要

NOVELTY - Preparing boron carbide nano powder comprises (i) mixing graphene oxide and boron powder, placing in a three-neck round bottom flask, adding ethanol and passing an inert gas, reacting under mechanical stirring, and allowing to stand, layering and removing the solvent to obtain a graphene oxide coated boron powder, (ii) placing the graphene oxide-coated boron powder in a heating device and passing inert gas for low-temperature heat treatment at 200-400 degrees C for 0.5-2 hours and cooling in the furnace to obtain boron carbide, and (iii) heat-treating the boron carbide at 800-1200 degrees C for 0.5-5 hours or a vacuum condition to obtain a boron carbide nano powder. USE - The method is useful for preparing boron carbide nano powder. ADVANTAGE - The method utilizes high specific surface area and high reactivity graphene oxide, reduces content of impurities and preparation costs, and improves purity.