Abstract: From July 17 to 23 in 2021, Henan Province was hit by serious flood-waterlogging disaster during the record extreme rainstorm. Zhengzhou City was the hardest hit, accounting for 95.5% of the deaths and missing persons in the Henan Province. In the main urban area of Zhengzhou City, there are major disasters such as the deaths of Metro Line 5 occurred, causing serious casualties and adverse social consequences. On the basis of finding out the sources of floodwaterlogging and the current situation of flood control and drainage, the characteristics of "7·20" extreme rainstorm, flood and waterlogging are analyzed. In accordance with the problems exposed during the "7·20" major disasters in the main urban area of Zhengzhou, the countermeasures and suggestions to deal with extreme rainstorm are proposed, such as reducing the hazard of rainstorm, improving the disaster prevention capacity of water works, reducing the exposure of bearing body and enhancing the resilience of urban flood defense.