Graft copolymer containing anhydride group and application thereof

A graft copolymer containing an anhydride group and an application thereof. The graft copolymer is a polymer containing an anhydride group and a side chain of a high molecular copolymer, and is mainly formed by means of the free radical polymerization of 40wt%-90wt% of a monomer A containing a carbon-carbon double bond, 5wt%-30wt% of an unsaturated monomer B containing an anhydride group and 5wt%-30wt% of a high molecular polymer C containing a carbon-carbon double bond. The preparation process is as follows: first, a high molecular polymer D is obtained by using free radical copolymerization, the high molecular polymer C containing a carbon-carbon double bond is then prepared by using a reaction between groups, and the graft copolymer containing an anhydride group is finally obtained after carrying out free radical copolymerization and drying devolatilization on the obtained high molecular polymer C, the monomer A and the monomer B. The graft copolymer containing an anhydride group of the present invention may be used as a compatibilizer for polymer blends and glass fiber reinforced materials.