Physics-of-Failure (PoF) represents one approach to reliability assessment based on modeling and simulation that relies on understanding the physical processes contributing to the appearance of the critical failures. Firstly the connotation and meaning of PoF method were analyzed here, the inherence relation between PoF and reliability was expatiated, the PoF based reliability method and current reliability method based on probability statistics were compared, their differences and relationships were discussed here. Then the application condition of PoF method in reliability engineering in European and American developed country and China were summarized, the PoF based reliability engineering technologies were introduced systemically from several aspects, such as reliability design and analysis, reliability test and validation, maintain and support. Finally, combining with the developing characteristics of military materiel during the new period, some future investigation directions and application foregrounds were prospected.