Abstract: Deep foundation pit is a high-risk project, in which the theories are complex and discipline is highly comprehensive. It often appears bracing system instability, retaining structure instability, pit wall leaking , bottom uplift and so on. Combined with a project example in Shanghai, the main points of selecting scheme of foundation pit support were analyzed. And the key calculations and checking content in the design of retaining structure are Summisized. Finally, design calculation results and the practical monitoring data results are compared. The conclusion had proved the effectiveness of retaining form. It provides some suggestions for same type of deep foundation pit projects.