Dozens of 10, 000 t berths and deep-water waterways are planned to be constructed in Tieshan Bay sea area, which will result in the change of tidal current and sediment motion due to land reclamation. Based on methods of unstructured grid and dynamic stability margin (DSM), a planar 2-D model is built up to imitate the tidal-field’s change and analyze the back-silting intensity and quantity in the construction area, so as to solve the technical problems concerning the tidal current and sediment and provide a scientific foundation for the optimization of the project.