Abstract: With the development of cascade power stations, the influence of backwaters on the power generation of upstream power stations is becoming more and more common.It is important to analyze the changing law of power generation by the backwater effect and study optimization strategies to improve the power generation of cascade power stations.In this paper, the changing law of tail water level and power generation index of Wan'an Power Plant before and after Jinggangshan Reservoir's operation was studied by applying the backwater calculation and runoff regulation models, and the corresponding dispatching operation strategy was preliminarily studied.The results showed that the water storage of Jinggangshan Reservoir has a significant impact on the tail water level of Wan'an Power Plant, and reduces power generation by 0.99 million kW·h on an annual average.The influence degree of the power generation head of Wan'an Power Plant gradually decreases with the increase of the inflow, and the maximum reduction value of the power generation head is about 3.91 m; The dispatching operation strategy that raising the water level of Wan'an Reservoir during the water supply period(from November to February)could improve the power generation significantly.The research results can provide a certain reference for the generation dispatching of other similar power stations affected by backwater.