Abstract: The foundation pit enclosure is not only subjected to the unloading effect of soil, but also to the self-weight load of vehicles in metro station construction by semi-pavement method. Therefore, it is necessary to study the deformation and internal force variation of the pit support structure during metro construction to ensure the stability of the foundation pit. Taking a metro station as the case study, the deformation law of the retaining structure during the foundation pit excavation is studied through numerical simulation and construction site monitoring. The conclusions are as follows: 1) the numerical simulation shows that the maximum horizontal displacement of the middle pile top is 6.54 mm and the maximum settlement value is 5.8 mm; 2) the settlement around the foundation pit presents an “inverted pot” type from near to far, the settlement changes are most obvious when the foundation pit is excavated from 13 m to 19 m, and the ground settlement will reach the maximum value of 8.914 mm at 4.6 m away from the underground continuous wall. The field monitoring data have verified the correctness of the numerical simulation results, and factors affecting the foundation pit stability are analyzed according to the engineering geology, monitoring data and the surrounding environment.