▎ 摘　　要

NOVELTY - Preparing lignin-based graphene quantum dots involves performing enzymatic pretreatment of lignin, adding enzyme to reactor containing lignin for enzymatic hydrolysis pretreatment to obtain pretreated lignin. The lignin pretreated is charged into high-pressure reaction kettle for hydrothermal reaction. The reaction product obtained is first centrifuged followed by dialysis to obtain aqueous solution of lignin-based graphene quantum dots. USE - Method for preparing lignin-based graphene quantum dots used in field of information encryption (claimed). ADVANTAGE - The method enables to prepare lignin-based graphene quantum dots that is green and environmentally friendly, simple and easy to operate, conducive to environmental protection, characteristics of uniform size, high yield, good water solubility, important practical significance for macro preparation of graphene quantum dots.