The work aims to summarize the researches on the dielectric properties of the polymer matrix composites improved with the modified graphene in recent years, and to point out the future development direction. The method regarding the modified graphene used to improve its dispersity in the polymer and to enhance the dielectric properties of the polymer-based graphene composites was summarized. By comparing the effects of compound technology of graphene/polymer matrix composites on the change in their dielectric constants and dielectric loss, the influence of different modification methods on the dielectric properties of the composites was summarized. The results show that as the conductive filler with excellent properties, the graphene has huge influences on the dielectric properties of the materials. However, its poor physical dispersity greatly hinders the development of modified graphene/polymer based high dielectric composites. Through functional modification of grapheme, it can effectively improve the dielectric properties of polymer matrix composites. Such material can be used as electroactive polymer and applied in many dielectric fields requiring high dielectric constants, such as supercapacitor, sensor, actuator, smart packaging and robot.