To identify the influence degree of tunnel construction on adjacent buildings, the strength reduction coefficient and the progressive failure mode of the tunnel are analyzed based on the strength reduction method. The static and dynamic indexes of the adjacent zone are defined. Then, a numerical calculation orthogonal test is conducted based on the different positional relationships between the Chongqing Qiansimen tunnel and surrounding buildings. The safety factors of 2.4 and 2.0 are used to determine the boundary of strong, weak, and non-influencing zoning in Grades Ⅴ and Ⅳ rocks. Based on mathematical statistics, the zoning formula of the influence of high-rise buildings adjacent to the tunnel and the elliptical influence zoning map are established. Taking the Qiansimen tunnel passing through the Huaxia Bank Mansion as an example, the accumulated settlement of foundation obtained by simulation calculation is 15.6% larger than the monitored value, which shows that the established influence zoning map of the adjacent buildings of the tunnel has certain rationality.