▎ 摘　　要

NOVELTY - Preparing aldehyde-based graphene involves mixing graphene with Vilsmeier reagent, heating, reflowing, subjecting to imidization reaction with Vilsmeier reagent to obtain graphene imidization, hydrolyzing graphene imidization to give aldehyde-based graphene, where Vilsmeier reagent is prepared by reacting N,N-dimethylformamide with phosphorus oxychloride. USE - Method for preparing aldehyde-based graphene for preparing graphene composite material (claimed). ADVANTAGE - The method enables to prepare aldehyde-based graphene that has good dispersion in the matrix. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for: (1) a method for preparing graphene composite material, which involves using aldehyde-based graphene and/or alkylated graphene as raw material; and (2) a method for preparing alkylation graphene, which involves mixing aldehyde group-graphite alkene and organic alcohol in acidic condition to obtain alkylated graphene.