▎ 摘　　要

NOVELTY - Preparing graphene quantum dot by combination of ultrasound and microwave comprises (i) adding sodium hydroxide and graphite into N-methylpyrrolidone to obtain mixed solution, (ii) adding the mixed solution in an ultrasonic cleaner for ultrasonicating and then placing in ultrasonic cell crushing machine and ultrasonic crushing, and reacting by microwave radiation heating, and (iii) dialyzing, filtering, rotary evaporating and concentrating to obtain final product. USE - The method is useful for preparing graphene quantum dot by combination of ultrasound and microwave. ADVANTAGE - The method: is simple and suitable for large scale industrial production; and has low energy consumption and high yield product.