Abstract: Based on the "July 20, 2021" extraordinary rainstorm scenario in Zhengzhou City, this paper carries out a quantitative analysis of the risk area of waterlogging in the central urban area of Wuhan City and identifies the key protection objects. Through the analysis of the water recession process of the direct- drainage water system and the regulated storage water system in Wuhan, the highest water level and recession time of the regulated storage lake under different working conditions are predicted. And then, it proposes strategies to deal with the extreme rainstorms and waterlogging from the standard waterlogging prevention system, analysis of emergency trigger conditions for exceeding the standard waterlogging risk, and key defense measures.