Sand excavation and channel regulation in Dongjiang delta have great impacts on the natural evolution of the river network area riverbed morphology. The two-dimensional tidal flow mathematical model is used for the tidal current study of Daoyunhai waterway, in which the finite volume method is adopted. On the basis of the model verification against the field-measured date, numerical simulation of tidal flow field before and after regulation is carried out. The treatment scheme of the hydrodynamic is calculated, and the river network channel regulation from the point of view of the dynamic field is analyzed. The study results show that the impact on the flow of water after implementation of the project mainly concentrates in the vicinity of the project. The impact on the drop, flow rate and water level of the river are small. Moreover, it provides the theoretical guidance of channel regulation in the tidal river network area.