Abstract: Due to the climate change, extreme weather and human activities, the water, rain and engineering condition in Changjiang River Basin were changed. In the flood season of 2020, Chaohu Lake Basin experienced a super-historical flood because of the continuous heavy rainfall and the high water level jacking in the Yangtze River. The water level in Yuxi River, Niutun River, Yongan River and other major tributaries in the basin were all above the warning level, and some tributaries even exceeded the guaranteed level, and the duration time of high water level was the longest among all rivers and lakes in the Changjiang River Basin. Aiming at the exposed problems of Chaohu Lake Basin, such as insufficient space for flood storage, difficult discharge capacity of river channel, the lower flood control ability of local areas, we analyzed the reasons and proposed optimization suggestions and countermeasures to the flood control system of Chaohu Lake Basin, which can provide thoughts and methods for promoting the flood control ability and revising the flood control planning.