▎ 摘　　要

NOVELTY - Auxiliary device comprises supporting body, buffer layer which is arranged on upper surface of supporting body, where buffering layer is provided with multiple penetrating buffer layer of hole. USE - Auxiliary device for preparing graphene (claimed). ADVANTAGE - The auxiliary device reduces graphene nucleation density and growing speed of graphene. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a method for preparing graphene, which involves: (A) placing substrate in chemical vapor deposition apparatus on substrate, where supporting body of auxiliary device is in contact with substrate, heating cavity to preset temperature; (B) discharging air in cavity, filling carbon source and maintaining temperature of chamber at preset temperature; (C) stopping inletting carbon source, filling protective gas in cavity; and (D) reducing temperature of cavity.