Construction of a real estate project is close to one side of the metro station which has finished main structure building. The diagram of the metro station is used as supporting during the excavation of the pit of the real estate project, which will result in the one side unloading of the metro station. Bearing the unbalanced soil pressure, the metro station will have additional deformation and internal force. During the pit design, the additional deformation and internal force is analyzed for every step of the excavation. And the additional force is superimposed with the original force of the metro station to calculate the final internal force of the metro station. By adjusting the design parameters of the pit, the safety of the metro station is evaluated.