▎ 摘　　要

NOVELTY - Preparing graphene involves purifying graphene production waste water or/and concentrating, putting graphite in potassium permanganate and processing, uniformly mixing graphene production waste water, reacting at 0-100 degrees C for 10-240 minutes, adding water to dilute, continuously reacting for 1-15 minutes, and filtering to obtain filtrate and filter cake. The filter cake is washed by water, washing liquid is mixed with the filtrate to obtain production waste liquid. The filter cake, water and hydrogen peroxide solution are mixed and stirred for 1-15 minutes to obtain intercalated graphite. The intercalated graphite is separated out, dissolved in water, and then placed in the microwave reactor, protective gas is filled, reacted for 1-15 minutes to obtain graphene. The operation is repeated for 3-5 times. USE - Method for preparing graphene. ADVANTAGE - The method enables to prepare graphene that is suitable for large-scale popularization, has high yield and good quality, and reduces the production cost.