According to the construction and monitoring method taken in the drilling and blasting subsurface excavation for shield machine introduced segment of Dalian metro line No.2, the paper analyzed the variation of the settlement of surrounding ground and buildings caused by the construction. And with the aid of midas GTS software, the paper also established a three-dimensional finite element model of the tunnel to make a live digital simulation for the state of tunnel deformation and surrounding rocks, so as to figure out the law of soil disturbance by comparing the simulation results with the actual monitoring data, and also to predict and estimate the stability of the surrounding tunnel rocks and the safety of the primary support structure through precisely analyzing causes of the variety of settlement and deformation. Meanwhile, the paper can provide reference for design and operation of analogous constructions.