▎ 摘　　要

NOVELTY - Method for preparing double-layer graphene, involves (a) providing a metal substrate, a reducing gas and a carbon source, (b) subjecting the metal substrate to heating treatment and annealing treatment, and (c) adding the carbon source, and forming double-layer graphene on the surface of the metal substrate through a chemical vapor deposition reaction, where the carbon source is a gaseous carbon source in the chemical vapor deposition reaction. In the step of heating treatment, before the temperature rises to 750 degrees C, the reducing gas is introduced to pretreat the metal substrate. USE - The method for preparing double-layer graphene, which is used as a double-layer graphene film (claimed). ADVANTAGE - The double-layer graphene prepared by the preparation method is a full double-layer graphene, and has a uniform and stable structure. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a double-layer graphene, which is prepared by the method for preparing the double-layer graphene, where the double-layer graphene is a double-layer graphene film with a coverage rate greater than 99%, and lateral size is 0.1-100 cm.