Abstract: By adopting Plaxis 3D finite element analytical software, a finite element model is established to simulate foundation pit excavation construction process. The influence of parameters including the distance between foundation pit and the tunnel, the foundation pit excavation depth, and shield tunnel segment thickness on tunnel segment convergence deformation is studied. The field measured data of existing projects has verified the effectiveness of the model. Research results show that the distance between foundation pit and tunnel has the biggest influence, segment thickness is second to it, and the foundation pit excavation depth the least.