Taking the reclamation and filling project of T7，T8，T9 area in Tianjin Port-vicinity Economic Zone as an example,we analyze the characteristics of bank slope and the structure of soil layer in the construction area.By optimizing the traditional construction technology,we realize the efficient excavation construction of the bank slope by construction ships.Through the detailed introduction of the construction process,we provide a solution for the excavation of super long underwater bank slope under complicated geological conditions.We also summarize the construction experience to further optimize the construction technology for the cutter suction dredger.