The invention relates to a modification method of graphene, particularly a chemical modification method of surface graphene on the basis of solid-phase thermochemical reaction. The invention aims to solve the problems of complex operating technique, environment pollution and difficulty in scale-up in the existing graphene modification process. The method comprises the following steps: 1. cleaning to obtain cleaned copper foil; 2. growing graphene to obtain copper foil with graphene grown on the surface; 3. loading the graphene to obtain the graphene-loaded matrix; and 4. carrying out solid-phase thermochemical reaction to obtain a matrix loaded with chemically modified graphene, thereby completing the chemical modification of the surface graphene on the basis of the solid-phase thermochemical reaction. The method has the advantages of simple operating technique, controllable reaction, no pollution and simple equipment, and lowers the production cost. The method is mainly used for surface graphene chemical modification.