Abstract: To analyze the effect of retaining structure on dewatering wells in deep foundation pit, a dewatering project of deep foundation pit in Suzhou Metro Line 4 is taken as an example. First, the initial design project and the optimized design project which considers the effect of building envelope are compared. Second, Modflow is used to simulate changes of water level and to evaluate the rationality of the design. The results show that the initial design project which does not consider the effect of retaining structure causes the water level no uniform, and the maximum water level difference reaches 3.5 m. While the optimized design project can make water level uniform, and the maximum water level difference is only 0.5 m, which satisfies the dewatering requirements.