▎ 摘　　要

NOVELTY - Method for preparing layered graphene, involves (a) subjecting graphite powder for purification, (b) directly adding the powder in high pressure kettle or dispersing in a solvent in a high pressure kettle, heating high pressure kettle to 35-60 degrees C, and pumping the fluid through supercritical fluid pump to a pressure kettle, (c) increasing pressure to 75-300 atmosphere (Atm), stirring for 30 minutes to 20 hours, reducing pressure to 1 Atm in 5-20 seconds, and (d) autoclaving the high pressure kettle, and obtaining few layered graphene. USE - The method is useful for preparing layered graphene (claimed). ADVANTAGE - The method is rapid, simple and environmentally-friendly, has short reaction period, and produces highly-integrated graphene layers. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: (1) graphene powder produced by the above-mentioned method; and (2) graphene preparation device, comprises stirring motor, heating set, high pressure kettle, gas circulation system, stirring pole, stirring head, where the stirring pole is provided vertically on the top portion of the device and one end of the stirring pole is connected with stirring motor, sample inlet and gas entrance which are provided at two sides of stirring motor, heating set covered on the high pressure kettle, outlet provided at the bottom of the high pressure kettle, gas circulation system comprising gas tank, first valve, second valve, flow meter, condensing device and third valve.