▎ 摘　　要

NOVELTY - A graphene is produced by putting graphite powder and dispersant in high pressure kettle; pre-setting temperature in the high pressure kettle, and pumping carbon dioxide; after the carbon dioxide flow time reaches a predetermined value, quickly reducing the pressure in kettle to normal pressure; and repeating the steps to obtain graphene. USE - Method for preparing large scale graphene (claimed). ADVANTAGE - The method does not destroy quality of graphene, uses non-toxic and inexpensive carbon dioxide, and has simple operation and low cost.