Abstract: The Lingdingyang area of the Pearl River Estuary is affected by superposition of multiple dynamic forces including tides, river runoffs and typhoons, resulting in a complex sediment transport process. However, study of the impact of seabed sediment erodibility (characterized by critical erosion stress) on sediment transport remains insufficient. For this reason, the sediment transport process under the influence of spring tide, neap tide and Typhoon Hato is simulated and the effect of seabed erodibility on sediment movement in the Lingdingyang area is investigated by integrating the sediment consolidation model proposed by Sanford into the ECOMSED 3D water-sediment model and setting up a reference case (the actual critical erosion stress) and two experimental cases with enhanced erodibility (with the critical erosion stress being 1/2 and 1/8 of the reference value, respectively). The results show that the seabed erodibility has a significant impact on the spatial distribution of suspended sediment. The decrease of critical erosion stress can increase the concentration of suspended sediment in high turbidity zones and tend to expand toward downstream the distribution range of suspended sediment, which is more obvious in strong dynamic scenarios such as typhoons. The response of seabed scour and silting to erodibility varies: changing from silting to scour in the northern area during low tides, increasing erosion intensity during high tides and changing to strong erosion across the entire area in typhoon periods. The sediment exchange between the estuary and the open sea is affected by critical erosion stress. When the critical erosion stress decreases to 1/8 of the reference value, the proportion of sediment transported to the open sea increases significantly and when to 1/2 of the reference value the sediment output changes gently. This study clarifies the mechanism of influence of seabed erodibility on sediment transport in the Lingdingyang area and can provide a basis for optimizing the seabed sediment parameters of the Lingdingyang water-sediment model and also has reference value for the study on similar estuaries with cohesive sediments.