In order to clarify the mechanical response characteristics of adjacent tunnels during excavation,the deformation and internal force of tunnel segments were analyzed by finite element numerical simulation software. The influence of groundwater seepage on adjacent tunnels during excavation was analyzed by controlling the change of water head and pressure during excavation. The results show that the excavation of foundation pit will lead to the deformation and internal force changes of adjacent tunnels. The deformation and internal force of the tunnel will increase significantly when the seepage of groundwater is considered. This study can provide a reference for evaluating the safety of adjacent tunnels and the design and construction of related projects.