Abstract: It has a high risk to excavate foundation pits in soft soil areas, and the impact of foundation pit excavation on adjacent subway tunnels must be strictly controlled in the subway security area. Therefore, the deformation control on designing of foundation pit support in subway security areas under soft soil conditions is highly demanded. The support design scheme of a deep foundation pit in Shenzhen's reclamation area and subway security zone is introduced in detail. The design scheme is analyzed and verified by rational element calculation and three-dimensional finite element calculation, and the calculation results are also compared with the monitoring data. The analysis shows that the form of occlusal piles + reinforced concrete support structure has high reliability in the application of deep foundation pits in soft soil. The monitoring data is applied to three-dimensional finite element to conduct inversion analysis, which can assist in the design and predict the deformation of the supporting structure and the adjacent subway tunnel, so as to adjust the supporting measures in engineering projects.