Located in Yaosha and Lengjiasha area of Nantong city,Tongzhou Bay Port stands on the southern margin of the radial sandbar with large beach surface exposure at low tide and large tidal range.The scale of Tongzhou Bay Port Area plan is large,which requires massive land reclamation to form the port area,with the prerequisite of sea dike building.By studying the basic data of wave,tidal current,geology and etc.,and combining with the model test and engineering practice,we study the key technology of dike design under the environment of high tides and silty-sand foundation,so as to provide reference and experience for subsequent projects from dike elevation,material,analysis of skid resistance,seepage and scour prevention,construction essentials,etc.