[Objective] In typical plain tidal river networks at the Yangtze River Delta front， dense waterways and frequent navigation significantly impact levee safety through channel operations and bed scour. Focusing on two typical levee structural types along the Huangpu River and its main tributaries， this study investigates the scour response under the coupling of structural dimensions and scour depth. The findings aim to provide a scientific basis for accurately identifying high-risk bank sections， optimizing bank protection structures， and enhancing the targeted management of levee engineering in tidal navigable rivers. [Methods] To examine the scour resistance sensitivity and its variation of levee structures in tidal navigable rivers， the theoretical scour depth was calculated based on the actual operating conditions of a navigable tributary in the upper Huangpu River. Using these calculated values as a reference， finite element models were developed to analyze the displacement responses of gravity-type and pile-founded levees under coupled conditions of varying structural dimensions and scour depths. This approach allowed for the determination of the scour resistance sensitivity and evolutionary trends for different levee structural types. [Results] The scour resistance sensitivity of gravity-type levees is primarily influenced by the base slab width and embedment depth. When the base slab width is <4 m or the embedment depth is <2 m， a toe scour 0.5-1.0 m triggers a sharp increase in the displacement rate at the wall top. Conversely， when the base slab width exceeds 5 m or the embedment depth exceeds 2 m， further increasing the dimensions yields significantly diminishing returns in scour resistance. The scour resistance sensitivity of pile-founded levees is mainly governed by the pile length. When the pile length is <15 m， the displacement growth rate accelerates markedly once the scour depth 1.0-1.5 m. Beyond a pile length of 15 m， the effectiveness of increasing pile length to enhance scour resistance weakens. [Conclusion] （1）The sensitivity of different structural types to toe scour must be fully considered during the selection and sizing of levee structures in tidal navigable rivers. Under the given typical boundary conditions， the scour resistance sensitivity increases with the base slab width， embedment depth， and pile length. However， beyond certain thresholds， the marginal gain in sensitivity decreases， making it economically inefficient to further improve scour resistance solely by enlarging structural dimensions. Instead， altering the structural type or controlling the scour depth is recommended to enhance levee safety. （2）For the design of gravity-type levees， it is advisable to maintain a base slab width of ≥4 m and an embedment depth of ≥3 m. If the anticipated scour depth exceeds 1 m， gravity-type structures are not recommended. For existing gravity levees， the impact of scour should be mitigated through strengthened vessel traffic management and the installation of protective structures. （3）For the design of pile-founded levees， the pile length should be controlled at ≥15 m. When the anticipated scour depth reaches 1 m， measures such as enhanced vessel traffic management and protective structures should be implemented to reduce scour impacts. The proposed structural dimensions and structural adaptability under varying scour conditions provide a scientific basis for the design and management of levees in tidal navigable rivers.