Abstract: The Yangtze River No.1 flood in 2017 posed a serious threat to the middle and lower reaches of the Yangtze River. The Three Gorges Reservoir effectively alleviated flood pressure by flood storage and detention. This paper introduces the status of the Three Gorges Project in the flood control system of the middle and lower reaches of the Yangtze River;analyzes the effect of Three Gorges Reservoir on flood control compensation dispatching in the middle and lower reaches of the Yangtze River taking the Yangtze River No.1 flood in 2017 as an example;and calculates the research period. The results show that the Three Gorges Reservoir has obvious effect on flood control compensation dispatching in Chenglingji area.