Based on a practical engineering case study, this paper concludes the deformation law during foundation pit construction of deep soil horizontal displacement, supporting axial force and ground settlement, through analyzing numerous field measured monitoring data. In the actual construction process, the deep horizontal displacement of the soil is increasing with the depth of the excavation, and the position of the maximum depth is also dropping, with the curve in shape of a big belly. The axial force of the supporting shaft also increases with the construction of the foundation pit, and the additional second support effectively relieves the axial force of the first support. However, the axial force of both supports increases at a rapid rate until the completion of project. Both the surface subsidence and the displacement of surrounding pipeline also keep increasing with the construction progress. The conclusion of this paper can provide references for similar projects.