Coastal tidal flats are important land reserves, as they have significant potential for enlarging living space. Based on the characteristics of coastal tidal flats in Jiangsu Province, the guidelines, overall layout, and principles of large-scale development and utilization of tidal flats are discussed. It has been found that large-scale rapid reclamation and other human activities have large impacts on the offshore environment. The impacts of large-scale development and utilization of tidal flats on offshore dynamic conditions and the ecological environment are discussed, and corresponding environmental protection measures are provided.