A 2-D tidal current and sediment mathematical model for Meishan waterway sea area is established on the basis of analyzing the measured data. After flow and sediment motion verification， the model is applied to calculate and analyse the changes of the tidal current and the erosion-siltation variation caused by the anchorage shelter project under typical spring-neap tide conditions. The research results show that the flood and ebb tidal volume in the Meishan waterway constitutes a small percentage of those of the surrounding waterways， bringing no changes of the flow field and sediment balance in the large sea area. Cumulative deposition trend is shown in recirculation and slow-flow region near the proposed two dikes at the south and north waterways because of velocity decreasing, which will give some impacts on the water conservancy facilities located in the adjacent areas. Therefore it is necessary to take protective measures to ensure safe operation of the small sluices and wharfs located in the sea area. The analysis research findings can provide a technical support for the project design and construction.