Method for rapidly preparing high-purity graphene powder with stable layer number by utilizing fixed bed

The invention discloses a method for rapidly preparing high-purity graphene powder with a stable layer number by using a fixed bed. Comprising the following steps: S1, taking a copper plate as a substrate, cutting, punching corresponding positions on two sides, cleaning, and fixing the copper plate on a graphite bracket at intervals by modules; s2, placing the copper plate and the support carrier in a fixed bed reactor, sealing a furnace chamber of the reactor, discharging internal air, continuously introducing inert gas in a normal pressure state, then heating the copper plate to a near melting point, introducing carbon source gas, and moving the copper plate and the graphite support frame to a quenching end for rapid quenching after graphene film growth is completed; s3, placing the whole in a solution for ultrasonic separation, washing the copper plate/graphite bracket, and airing for reuse; and S4, filtering, drying and crushing the graphene to obtain the small-size graphene powder. The preparation method