The construction of rivers and lakes (including transforming natural rivers and lakes and digging artificial rivers and lakes) has achieved remarkable results in preventing drought and general floods, which has promoted the development of agriculture in Taihu Lake Basin. However, Taihu Lake basin is often hit by typhoons and rainstorms, including strong typhoons and rainstorms, and the daily rainfall can reach hundreds of millimeters. Will form a catastrophic flood, in the face of catastrophic floods, these projects will appear weak. As far as Hepu is concerned, restricted by the dish-shaped topography of Taihu Lake Basin, the slope is very small, and it is impossible to quickly discharge catastrophic floods into rivers and seas. As far as Hubei is concerned, it is not as strong and tall as the later large reservoirs, and it is unable to accommodate a large number of floods. The flood volume is large and the storage capacity is weak, which makes the flood disaster inevitable. The ancients worked hard to build farmland water conservancy in Taihu Lake basin, but floods still occurred frequently, which should be said to be the main reason.