▎ 摘　　要

NOVELTY - Preparing graphene involves providing a substrate, placing substrate in a reaction chamber, performing annealing pretreatment on the substrate, and introducing a carbon source, and performing a chemical vapor deposition reaction on the substrate after the annealing pretreatment to grow graphene. The annealing pretreatment further includes introducing water vapor into the reaction chamber to etch the surface of the substrate, and the graphene grows on the surface of the substrate after the etching. USE - Method for preparing graphene. ADVANTAGE - The method enables to prepare graphene, that anneal surface of the substrate and pretreated with water before the graphene is grown, so that the graphene can be directly grown on the insulating substrate with high quality, and large-area graphene has broad application prospects in the semiconductor field. DESCRIPTION OF DRAWING(S) - The drawing shows the flowchart of a method for preparing graphene. (Drawing includes non-English language text).