For the construction of sand bag cofferdam on the super soft foundation at sea,the cofferdam is prone to uneven settlement and unstable foundation due to the deep silt and poor bearing capacity of the foundation.At present,the state has strict approval for the sea use,and the construction process is strictly prohibited to use the red line beyond sea use.So,it is impossible to dissipate the load by using traditional technology to increase the bottom bearing sand bag or front riprap and fill of cofferdam.Through the stress analysis of the formation process of sand-bag cofferdam and based on the typical section test,we adopt integral long sand-bag embankment to deal with the uneven settlement of sand-bag cofferdam,which ensures the uniform stress in the process of the sand-bag levee construction,reduces uneven settlement,and speeds up the construction.