Abstract: Dynamic reliability method can make up the shortage of traditional Event Tree/Fault Tree method. It can be used to complete the current reliability and safety assessment methods of nuclear power plants. In recent 30 years, a relatively perfect theory foundation (probabilistic dynamics) has been developed. On this basis, Monte Carlo simulation and discrete dynamic event tree were formed. The research situation and technical characteristics of the dynamic reliability theory and method were introduced. And the future trend of dynamic reliability was also discussed.