▎ 摘　　要

NOVELTY - Preparing layered graphene comprises providing crystalline graphite, and subjecting the crystalline graphite to the reaction liquid and the dispersant to a first mixing treatment to obtain a first mixture, subjecting the first mixture and the activator to a second mixing treatment to obtain a second mixture, post-processing the second mixture to obtain the layered grapheme, where the reaction liquid is chlorosulfonic acid, perchloric acid and/or sodium perchlorate and the activator is hydrogen peroxide, sodium bicarbonate, and/or sodium peroxide. USE - The method is useful for preparing layered graphene. ADVANTAGE - The method: achieves effect of physical gas phase exfoliation, exfoliates the crystalline graphite in a gas phase environment to prepare layered graphene. DETAILED DESCRIPTION - AN INDEPENDENT CLAIM is also included for layered grapheme is a layered graphene with a structure of 1-20 layers, and the sheet diameter of the layered graphene is 3-8 mu m.