Prognostics and Health Management (PHM) technology of the avionics system can greatly improve the safety, reliability and stability of aircrafts, so as to reduce the maintenance costs. The structure and management functions of Integrated Modular Avionics (IMA) system are briefly introduced.Based on ASAAC Standard and OSA-CBM model, the design of PHM for IMA system is analyzed from the aspects of the structure, function layer and tree-form Run-Time Blueprint(RTBP).Finally, according to the characteristics of avionics system, the application and development of future avionic PHM technology are discussed.