As more and more shields bore across underneath existing structures, the shield boring may jeopardize the safety of the existing structures inevitably. The running tunnel from Guanzhuang station to Wangjingxi station on line 15 of Beijing Metro crosses underneath the foundation of Wangjingxi station on line 13 of Beijing Metro. In the paper, the process of shield boring across underneath Wangjingxi station on line 13 of Beijing Metro under the condition of grouting reinforcement and non grouting reinforcement is simulated by means of ANSYS. The simulation shows that the deformation of the existing structure in the case of grouting reinforcement is reduced dramatically. Comparison and contrast is made between the ANSYS simulation results and the measurement results, which shows that there is no obvious difference between the ANSYS simulation results and the measurement results. It is concluded that the ANSYS simulation results are reliable. The paper can provide reference for other shield boring across underneath existing Metro stations in the future.