Abstract: During excavation of deep foundation pit, the bored piles combined with concrete struts have a positive role in retaining soil, while double waterproof curtain formed by cement-soil mixing piles and dense-compacted grouting can effectively cut off water. Based on the project of Suzhou performing arts center phase Ⅱ, measured datas in the process of excavation are given. Then the deformation of retaining structure, change of underground water, settlement of surrounding buildings are also analyzed and studied to verify design and construction projects of support structure and waterproof curtain of this example. The results show that these measures achieve good implementation. It could provide references and suggestions for similar foundation pit projects in Suzhou area.