Abstract: Dam safety management is a process of risk management and risk decision in essential. Since last decade, the technology of risk assessment has made great progress in the field of dam safety management in the developed countries. In this paper, based on the theory and method of risk assessment, risk analysis aiming to primary event on Fengman Dam has been carried out and study on dam failure risk has been made. The author has put forward some suggestion to dam rehabilitation which can be as reference to other similar projects.