Construction of sea dikes in coastal cities is often affected by adjacent bridges and tunnels,construction conditions are subject to various constraints.Therefore,this paper presents a low-pile wide-platform unloading-board seadike which is suitable for the disadvantageous conditions,such as small-size pile driving equipment,limited operation and construction area,bad geological conditions,no replacement of filler,heavy load to ground,high requirements of anticorrosion,etc.Three dimensional numerical simulation is carried out through MIDAS/GTS NX software,and deformation data are collected by field monitoring.The results show that the proposed structure plan has the advantages of small bending moment of pile foundation,small horizontal shift,good whole stability,etc.