Based on a large amount of experimental data,the rules was analyzed about the structure deformation,ground settlement and surrounding building deformation during excavation process.The monitoring results show that the deformation of the maintenance wall presents “spindles” shape,and has a space-time effect.With the increase of excavation depth,the maximum lateral displacement of diaphragm wall is constantly moving downward;surface subsidence curves show a “settling basin”,which means the subsidence reaches a maximum at a certain distance away from foundation pit edges,and the surface settlement gradually decreases as the distance increases,and the impact on surface subsidence in excavating deep soil is obvious;the settlement of the historical buildings can be controlled by reinforcing the lateral foundation enclosure and waterproof measures before excavating,as well as by the reinforcement of the historical building foundation.The conclusions provide some practical value and valuable reference for designing and excavating the soft soil foundation under crowded buildings.