Abstract: The construction level of high dams in China is leading in the world, but the guarantee level of their safety operation is relatively lagging behind. The high dams have relatively weak emergency support capability to deal with the extreme events such as flood, strong earthquake, geological disaster, abnormal drought, low temperature and terrorist destruction, thus their safety risks cannot be ignored. The review is carried out from three aspects: foundation and application basis, technical research and development, integrated demonstration and promotion. It includes: (1) The basic theoretical researches such as dam performance evolution and disaster mechanism under unconventional conditions, dam safety diagnosis and risk control under extreme conditions, early warning standards and emergency response mechanisms of dam failure; (2) Key technologies such as human-occupied vehicles for deep-water inspection of dams, deep-water leakage detection of dams, dredging and gate repair of deep-hole drainage structures, emergency monitoring of dams and rapid detection of their hidden dangers, defect repair of dams in deep water environment, emergency rescue and rapid repair of damage of dams under extreme conditions; (3) The integration demonstration of dam safety detection in 100 m-deep water, and the application and dissemination of early warning and emergency response of dam failure under extreme conditions. The latest researches on these issues are reviewed and summarized, and the relevant suggestions for the main development direction in the future are proposed.