There is A-line Qom subway with length of 14,700 meters and in 14 stations that A14 to A3 stations, with tunneling boring machine and A3 to A1 stations, step tunneling is predicted. This study examines the subject of the settlement between A3 to A2 station, which is drilled by step tunneling method. Using the FLAC3D software and determine strength parameters by back analysis, investigate the influence of tunnel excavation on the settlement of the ground's surface. Then range of face impact and also influence of BENCH excavation on the TOP tunnel during the different steps of progress has been examined. By using numerical modeling and analysing the results, the maximum of settlement reaches 1.52cm which enhance to 2.62 cm by BENCH excavation. Ground Settlement will increase by increasing in the excavation length step. Then it was paid to settlement by empirical and analytical equations and results are compared with numerical result that was seen suitable match. In another part of this study, using data instrument, a model was constructed in FLAC3D software and the results of the numerical and instrument methods are compared with each other. The results of the instruments and numerical methods measurements showed satisfactory compliance in the instrument gauges and convergence gauge.