Abstract: This article introduces the basic conditions and engineering features of the Tongma Dike on the Yangtze River, and analyzes defense features and effectiveness when it encounters flood disasters in 2020. During the prevention of the 2020 historical flood, measures such as reducing the water head of crossing culvert gate, analyzing the uplift pressure of medium-sized sluices in time, and dealing with the Bund dike defense according to the plan are taken for the sand foundations prone to piping, buildings through the embankment, and bund joints. The effective work should be carried out for the piping section, and the technical support role of the Yangtze River management unit should be actively played to ensure the Tongma Dike to spend the flood safely in the super-historical flood.