Based on remote sensing technology and its comparison with different types of information, changes in the coastline in Yancheng City were identified during the planned period of reclamation. Combined with field investigation and expert consultation, evaluation was carried out in terms of spatial layout of the reclamation area, functional zoning, sustainable supply capacity of tidal flat resources, ecological environmental protection, and construction of integrated experimental areas. The results show that, due to the slow development and reclamation of tidal flats in Yancheng City, the future reclamation plan should be locally adjusted according to the natural conditions and economic development requirements. With abundant tidal flats suitable for future development in Yancheng City, and with infrastructure construction coordinated with the development progress of the reclamation area, the tidal flat resources have high sustainable development capacity. Large-scale development and utilization of tidal flats will influence the dynamic conditions of water and sediment as well as the marine ecological environment. It is pointed out that an integrated reclamation environmental impact assessment model should be built based on the costal environmental characteristics, so that it will provide a basis for the sustainable development and utilization of tidal flats in the future.