Abstract: Peak discharge (PD) of the flood of the Three Gorges Reservoir (TGR) exhibits marked spatial variation because it is affected both by flood events of inflow tributaries and by reservoir operations. Study of the flood peaks and transport of the TGR based on inflow composition is helpful for elucidating the hydrodynamics of river-type reservoirs and supporting optimal dispatching of the TGR. This study investigated daily flow discharge at TGR hydrological stations during 2011—2020 by adopting hydrostatistics and river dynamics theories. The results indicated the following: ① The method proposed to determine the threshold discharge can efficiently record PD values at different stations during any flood event. ② Asynchronous occurrence of PD among different tributaries has little effect on the PD of TGR inflow when the PD value (Q_RK) is greater than 40 000 m³/s. ③ PD values at Qingxichang and Wanxian stations are determined by Q_RK, whereas PD values at Miaohe and Huanglingmiao stations are further controlled by TGR operations, leading to segmented change with Q_RK. Finally, formulas were devised to estimate PD at Qingxichang and Wanxian stations from the PD at Zhutuo and Beibei stations.