Abstract. Recently, in the field of high voltage equipment, polymer nanocomposites have received increasing attentions, due to their excellent electrical properties, such as high breakdown strength and high resistance to partial discharges, and their good mechanical and thermal properties, such as high mechanical strength and high heat durability and so on. In this article, the main preparation methods of polymer nanocomposites, including of blending method, intercalation compound method, in-situ polymerization method and sol-gel method, are reviewed, and the merits and faults of different methods are discussed.