Abstract: Graphene, a flat monolayer of carbon atom tightly packed into a two-dimensional honeycomb lattice, shows many unique physical and chemical properties and has good application prospect in various fields. Currently, the preparation and potential application of graphene and nano graphene composites have become the most important research frontiers. Herein, based on the structure and performance of graphene, the four preparation methods-mechanical exfoliation method, chemical vapor deposition method, chemical exfoliation method and chemical synthesis method are introduced. A comprehensive review is presented to introduce the preparation and potential application of nano graphene/polymer composites and nano inorganic/graphene composites. The unique advantages of nano graphene composites in biological medicine, electronic devices, microwave absorption, sensors and electrode materials are also reviewed. Future research and potential application of nano graphene composites are also prospected.