Graphene and its composites have received widespread attention in the field of energy storage as a new functional material. Compared with other preparation methods, electrochemical preparation technology has the advantages of safety, high efficiency and green. This article reviews the research progress of electrochemical methods for the preparation of graphene/nanometal composites, graphene/metal oxide (hydroxide) composites, graphene/polymer composites, and their applications in supercapacitors, in order to provide a reference for the research on electrochemical preparation of graphene and its composites in the field of superelectricity.