When the tunnel construction of metro shield section passes under the existing utility tunnel, the surrounding soil is inevitably disturbed, which will cause the deformation of surrounding soil, and will make the existing utility tunnel cause the additional stress and deformation, and threaten the safety of structure. In order to analyze the influence on the existing utility tunnel in the shield tunneling process, the deformation law of existing utility tunnel at the different crossing angles is explored. The three-dimensional finite difference method is used to simulate and analyze the settlement and deformation laws of the existing utility tunnel, the control effect of ground reinforcement to settlement of utility tunnel, and the influence of different crossing angles on settlement of existing utility tunnel in the process of shield tunneling. The calculation results show that the longitudinal uneven settlement of existing utility tunnel mainly occurs near the shied tunneling machine. With the shield tunneling, the settlement increases gradually. The ground reinforcement can effectively decrease the settlement and deformation of the existing utility tunnel. When the downward crossing angle is small, the settlement deformation of existing utility tunnel increases. The study result can provide the guidance for similar projects.