Abstract：Due to the space restraint，new parallel transfer metro station will be built close to the old station. The divisional walls will divide the long strip pit into several small pits that will be excavated alternately to keep the old station stable and safe during deep pit excavation. The longitudinal length of the old station is several hundred meters and the nearby excavation range in the divisional walls is tens of meters，so the station deformation in the excavation is restrained by its two side longitudinal station structure. When the pit is analyzed by three-dimensional shell finite element，the longitudinal restraint length of old station is changed. The parameter sensitivity analysis is made on the effect and the reference value is proposed.
