Abstract-PHM (Prognostic and Health Management) which isproposed by American army in JSF plan has gone through the fault diagnosis, fault prognostic and system integration three phases, and develops fast in both electronic and mechanical field. In this paper, the technical superiority of PHM is analyzed, and the framework of PHM for complex electromechanical equipment is built, which contains state monitoring, information processing and health management. Furthermore, the PHM system for complex electromechanical equipment is designed. At last, its application for DTG (Dynamically Tuned Gyroscope) shows that the system is feasible and usable.