Abstract: With the intensive development of urban underground space, disturbances to existing shield tunnels caused by adjacent foundation pit excavations have become increasingly frequent, posing a significant threat to the operation safety of existing tunnels. To investigate the influence of adjacent deep foundation pit excavation on the existing underlying shield tunnel structures and its optimized control strategies, the force and deformation characteristics of the existing twin shield tunnels under different zoned excavation schemes are analyzed by establishing a three-dimensional numerical model with the background of a deep pit excavation project above the existing twin shield tunnels. On this basis, the applicability of different control methods was compared, with a focus on evaluating the optimization effect of different loading conditions in controlling the uplift deformation of the tunnel. The results indicate that under the disturbance of deep foundation pit excavation, the additional stress in the underlying twin shield tunnels is dominated by the negative bending moments, with the maximum negative moment occurring below the middle section of the foundation pit. The primary deformation of tunnels is vertical uplift, which can be effectively mitigated through zoned excavation. Symmetric jump excavation from both sides of the pit towards the middle, sequential excavation, and symmetric excavation from the middle of the pit towards both sides reduce the uplift deformation by approximately 21.90%, 19.04% and 11.07%, respectively, compared to overall excavation. Increasing the length of the loading area and the magnitude of heaped loading can effectively enhance the control effect on the uplift deformation. It is recommended that the length of the loading area be approximately 80% of the underlying tunnel section length, with the secondary heaped loading greater than 200 kN/m. The findings of this study provide effective guidance for deformation control and safety protection of existing underlying shield tunnels subjected to disturbances from adjacent deep foundation pit excavation.