Abstract: The deformation of underlying shield tunnels caused by excavation and unloading of large-area foundation pits in soft soil areas is an important problem in actual engineering. Based on the deep foundation pit excavation project of Shenzhen Digital China Headquarters Base, the deformation characteristics of the underlying shield tunnel caused by the deep foundation pit excavation were studied. A three-dimensional finite element numerical calculation model was established using Plaxis3D numerical software, and the influences of different numbers of excavation division and soil reinforcement measures on tunnel heaving and pit bottom uplift deformation were analyzed. The research results showed that the excavation of the foundation pit had obvious spatial effects; the lateral deformation of the tunnel caused by the excavation was small with the maximum value only 0.92mm, the vertical displacement of the tunnel was influenced more with the maximum displacement of 14.26mm. Compared with the original excavation plan, an interval divided excavation could effectively control the tunnel heaving. Among them, a method of two sections of simultaneous internal divided excavation could control the heaving to the greatest extent, by which the heaving volume had been reduced by 25.9%. In addition, when the thickness of the reinforced soil was thin, it was not very significant for controlling the heaving of the tunnel. This study can provide a certain reference for the control of the heaving of tunnels and pit bottom uplift of similar engineering in soft soil areas.