Abstract: Conducting research on possible floods and their scheduling plans in the Dawen River Basin in Shandong Province is of great significance for the planning and comprehensive management of the Dawen River Basin. Taking the "7·20" extremely heavy rainstorm process in Zhengzhou as a typical rainstorm process in the Dawen River Basin, a practical scheme for watershed runoff generation and concentration is established, the possible flood process in the Dawen River Basin is discussed, and the regulation and storage capacity of the existing reservoir operation scheme for possible extreme floods is analyzed. The results show that if the "7·20" extremely heavy rainstorm in Zhengzhou occurs in the Dawen River Basin, the maximum water level of large and medium-sized reservoirs is lower than the design water level, and the average peak shaving ratio of reservoir flood regulation is 33.9%; The important sections of the main stream and tributaries exceed the guaranteed flow rate; Dongping Lake, without considering the diversion of Yellow River floods, adopts the method of using the old and new lakes in the West Lake area without breaking the Jinshan Dam to protect the old lake. The highest water level is 42.52 meters below the flood control operation level. The research results can provide reference for further improving the "four predictions" ability of forecasting, early warning, rehearsal, and contingency plan in the Dawen River Basin, and have certain engineering application value.