Taking the deep foundation pit engineering of integrated transport hub Ⅰ area in Shenyang north station as research object,the paper carried out field monitoring to structure and deformation of foundation pit retaining and analyzed the change rule of deformation of retaining structure in foundation pit construction process with excavation depth and time.By using finite difference software FLAC3D, the whole process of deep excavation support was simulated by 3d.It analyzed the deformation characteristics of the retaining structure after excavation of foundation pit, and carried out comparative analysis for field monitoring results. The results of numerical calculation are consistent with the measured results. The deformation rule of deep foundation pit can be studied by numerical simulation.