Abstract: Polyethylene glycol (PEG)/graphene composite phase change material was prepared by melt blending,and the degree of adhesion between PEG and graphene was improved by vacuum adsorption and additives.The research results showed that graphene could increase the crystallinity of PEG,improved the energy density of material,coupling agent and vacuum adsorption can improve PEG crystallinity,when PEG dosage was 95wt%,the graphene content 5wt%,samples prepared by vacuum adsorption D,the melting enthalpy and enthalpy of crystallization were 138.62J/g and 121.60J/g respectively,the highest in all samples.