▎ 摘　　要

NOVELTY - Preparing double-fluorescent graphene quantum dots involves reacting graphene solution with oxidizing agent i.e. hydrogen peroxide at 170 plus minus 5 degrees C for 60-65 minutes, where the obtained product is hydrothermally treated at 170 plus minus 5 degrees C for 75-80 minutes to obtain blue fluorescent graphene quantum dot solution. The blue fluorescent graphene quantum dot solution is added to deionized water, and then treated with manganese dioxide powder to obtain double-fluorescent graphene quantum dots. USE - Hydrothermal method for preparing double-fluorescent graphene quantum dots (claimed). ADVANTAGE - The method enables to prepare double-fluorescent graphene quantum dots with good water-solubility and little impurity.