In order to strengthen the flood management of medium and small rivers, a hydrological model, a Mike11 model, and a Mike21FM model were established. One- and two-dimensional hydrodynamic models were coupled using Mike Flood and were used to analyze the flood and waterlogging risks of medium and small rivers. Using the left bank area of the Fuxin River in Fengxian County of Xuzhou City as an example, a numerical model of flood routing was established to analyze the flood control capacity of the Fuxin River and the waterlogging of the study area during different rainstorms. The results show that the flood control capacity of the study area can meet the 20-year return-period flood control standard. The drainage capacities of some medium and small rivers were so poor that some regions showed serious waterlogging.