Abstract: In this paper, structure and characteristics of polyphosphazene were briefly introduced. The synthetic methods of hexachlorocyclotriphosphazene, poly (dichloro)phosphazene, and poly phosphazene were summarized. The progress on applications of polyphosphazene in aviation and military field was reviewed，including high-temperature flame retardancy coating, fire-resistant flame retardancy coating, flame retardancy foaming rubber, insulation of rocket motor, sealing materials. The existing problems of polyphosphazene material were pointed out. At last, the development of polyphosphazene material in the future was prospected.

Key words: polyphosphazene, flame retardancy, military, application, aviation