Abstract: With the continuous construction of hydropower projects, the problem of water body supersaturation caused by high dam discharge is becoming more and more prominent. In this paper, the research results for water body supersaturation at home and abroad in recent years were summarized, and the interaction between supersaturated total dissolved gas (TDG) and downstream aquatic organisms was analyzed from three aspects: fish tolerance, fish avoidance effect on supersaturated TDG and lethal mechanism of supersaturated TDG to fish, and then some research ideas were puts forward. Furthermore, this paper also focused on the progress and shortcomings in promoting the release rate of supersaturated TDG. It is pointed out that the release of supersaturated TDG under actual working conditions is influenced by surrounding environment such as river morphology, while the experimental conditions can not accurately reflect the actual working conditions, so the indoor tests and prototype observations need to be further strengthened in the future. And how to achieve rapid and efficient TDG release under the premise of safe flood discharge is the focus of further research in this field.