Abstract: Taking the deep and large foundation pit adjacent to a subway station in Suzhou as an example, the deformation caused by the deep and large foundation pit is controlled by using the principle of time and space effect and the pit dividing technology, and the safety of the close subway station has been guaranteed. The measured data of the surrounding environment are collected and analyzed. In the saturated soft clay area, based on reasonable pit division construction technology, the deformation of deep and large foundation pit during excavation could be controlled and the surrounding environment could be protected.