<p>The excavation of urban underground tunnel passes through the surface structure, and the surface will have obvious settlement and deformation, which will pose a serious threat to the construction safety. In this paper, based on the engineering example of tunnel excavation under the frame bridge of No.101 railway from Liaogongzhuang Station to Tiancun Station of Beijing Metro Line 6, the ground settlement caused by tunnel excavation and surface structures is theoretically analyzed, and the construction process of the frame bridge under the interval is numerically simulated and analyzed by FLAC3D software, and a similar model test is carried out, and then the measured ground settlement curve is verified to conform to Peck’s empirical formula by back analysis. Through the research and analysis of calculation results and measurement results, the following results are obtained: under the action of bridge load, there will be an obvious settlement groove on the surface in the longitudinal direction, and the settlement value of the surface at the boundary of bridge load is 1.29 times of the settlement value within the bridge load range; Moreover, the construction process has a great influence on the surface settlement, and the surface settlement caused by simultaneous excavation of tunnels on both sides is 79% of that caused by excavation of tunnels on one side first and then on the other.</p>