▎ 摘　　要

NOVELTY - Preparing graphene foam comprises pyrolyzing biomass, condensing the obtained pyrolysis gas to obtain gas mixture, purifying the gas mixture and vapor-depositing on the catalyst substrate, and removing the catalyst substrate. USE - The method is useful for preparing graphene foam. ADVANTAGE - The graphene foam has good electron transport performance and adsorption performance. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for a graphene foam preparing device, comprising a biomass pyrolysis device, a condensing device connected to the gas outlet of the biomass pyrolysis device, a purifying device connected with the gas outlet of the condensing device and vapor deposition device connected with gas outlet of the purification device.