[Objective] Physical clogging of riverbeds is a common problem in seasonal rivers，significantly affecting groundwater recharge and river ecological restoration. This study analyzes the infiltration and clogging characteristics of seasonal rivers，predicts the infiltration rates after riverbed disconnection，and provides scientific support for optimizing river ecological restoration and water replenishment schemes. [Methods] Taking the lower reaches of the Yongding River as a reference，five types of riverbed sediments with median particle sizes d₅₀ of 50， 100，150，300，and 600 μm were selected as experimental media. One-dimensional soil column infiltration simulation tests using 6 g/L muddy water were conducted to analyze the riverbed clogging characteristics and the transformation pattern from saturated to unsaturated flow. A prediction model for riverbed infiltration，considering the influence of physical clogging，was developed. [Results] 1）For fine particle riverbed with a median particle size of 50 μm，no significant clogging occurred. For riverbeds with particle sizes ranging from 100 to 600 μm， clogging occurred at a depth of 0 to 5 cm，and the hydraulic conductivity decreased by 86%，68%，93%，and 94%， respectively， compared to the initial values. 2） The 50 μm riverbed maintained saturated seepage throughout infiltration. For riverbeds with particle sizes ranging from 100 to 600 μm，the flow transformed from saturated to unsaturated seepage within 2.6 to 51.2 hours，with infiltration rates decreasing by approximately 15% to 30%. 3）A riverbed infiltration model considering clogging effects was constructed based on Darcy's law and the seepage formula for coarse particles. Model validation showed that the relative errors of the infiltration rates for four coarse-particle riverbeds（100-600 μm） were 8.6%， 14.7%， 22.1%， and 36.6%， respectively， and increased as the median particle size increased. [Conclusion] Fine sediment in muddy water has a significant impact on the clogging of coarse-textured riverbeds. The coarser the riverbed texture，the more likely it is to transform into a disconnected riverbed. A scientific understanding of the infiltration-clogging behavior of fine sediment in riverbeds of different textures is essential for optimizing ecological water replenishment schemes.