Method and device for continuously preparing large-area graphene thin film

The invention relates to a method and a device for continuously preparing a large-area graphene thin film. The device comprises a housing, a box type heating furnace, four reels, a vacuum system, a cooling system and a gas conveying system. The method comprises the following steps of: winding a curled copper foil on the reels and passing the reels through the hearth of the box type heating furnace; maintaining normal pressure or the vacuum degree in the range from 10 to 50 Pa in the hearth; evacuating the housing, and introducing argon or nitrogen to displace air in the housing; introducing argon or hydrogen into the hearth, preheating to 500 DEG C at first so that the fourth reel runs to drive the copper foil to pass through the hearth; when the temperature reaches the reaction temperature, introducing methane or acetylene into the hearth for reaction so that the graphene thin film begins growing continuously on the surface of the copper foil; when the graphene thin film is completely grown, stopping introdu