Abstract: To smoothly implement the large scale siltation promotion project of Nanhui side low tidal flat, in the light of the geological location, flow and sediment characteristics of 3 natural siltation promotion areas of 162 km2, the 2 D mathematical model was employed to analyze the general scheme of siltation promotion from the respects of the combination way of siltation promotion dyke and cofferdam, the siltation effect of separation siltation promotion and staged siltation promotion as well as economy. According the analysis results, we use the siltation-promoting dykes that stabilize the enclosure cofferdam and also act as tidal flat protection structure to realize river regime guiding and control, more deposition with low cost and speed up the tidal flat formation. In the same time, the siltation-promotion project implemented in advance in complicated flow field was researched in the aspects of flow dynamic change of various dyke sections under different siltation sequence. We suggest a scheme of first training dyke, then lateral separation dyke, first deep channel then shallow, first downstream separation dykes then the other lateral separation dykes. The practice showed that the siltation promotion scheme was good in implementation, the practical siltation was similar with the computation result. The correlative analysis method and experience can provide reference for the similar project.