As an effective way to control the stability of the surrounding rock in deep tunnels, drilling pressure relief can transfer the maximum principal stress to the deep part and reduce the surrounding rock stress in a certain range around the tunnel. On the basis of the actual situation of the three horizontal water storage tunnel project in Zhuxianzhuang, Huaibei, numerical simulation methods are adopted to for an analysis of the distribution characteristics of the maximum principal stress and surface displacement of typical parts of the tunnel surrounding rock under different pressure relief borehole diameters (50, 80, 100, 150, 200 mm), different pressure relief borehole lengths (3, 6, 8, 10, 15, 18, 20 m), and different borehole spacing arrangements (single row holes, spacing of 1.5 m×1.5 m, 1.0 m×1.0 m, 0.5 m×0.5 m) in the deep roadway of Anhui Lianghuai mining area, thus obtaining the reasonable drilling and pressure relief parameters for the tunnel, which can be applied in practical engineering, so as to achieve good results.