▎ 摘　　要

NOVELTY - The method for preparing large-area double-layer graphene film on insulating substrate, involves (i) preparing composite substrate that includes an outer copper tube, arranging an insulating substrate inside the copper tube which is made by curling a copper foil into a tube shape and acts as a catalyst, (ii) placing composite substrate into a reactor, introducing gas mixture of argon and hydrogen into reactor, (iii) heating composite substrate, (iv) maintaining constant temperature, adding gaseous carbon source, and reacting under the action of copper catalyst. USE - Method for preparing large-area double-layer graphene film on insulating substrate. ADVANTAGE - The large-area double-layer graphene film on insulating substrate is prepared easily in a simple manner. DETAILED DESCRIPTION - The method for preparing large-area double-layer graphene film on insulating substrate, involves (i) preparing composite substrate that includes an outer copper tube, arranging an insulating substrate inside the copper tube which is made by curling a copper foil into a tube shape and acts as a catalyst, (ii) placing composite substrate into a reactor, and introducing gas mixture of argon and hydrogen into the reactor, filling mixed gas in the reactor, (iii) heating the composite substrate, so that the composite substrate copper tube and the insulating substrate reaches the target temperature of 1000-1050 degrees C, and maintaining the temperature constantly for 30-120 minutes, (iv) maintaining constant temperature, adding gaseous carbon source into the reactor, and reacting under the action of copper catalyst to obtain large-area double-layer graphene film on the surface of the insulating substrate.