High ground stress and structural plane development are the key issues in controlling the stability of the surrounding rock mass of caverns in the process of excavating deep tunnels. Aiming at solving the stability problems of rock mass surrounding the deep-lying and high-stress hydraulic diversion tunnels, we used hydraulic fracturing method and three-dimensional hydraulic fracturing method to monitor and analyze the ground stress of a deep-lying high-stress tunnel project of a power station in Xinjiang. The discrete element software 3DEC was used to simulate the variations of stress field, the plastic zone and the displacement field of the surrounding rock mass, in order to study the stability of the rock mass. The results showed that the measured maximum principal stress was in the range of 12.4-12.9 MPa. The numerical simulation showed a plastic zone of 0-2.1 m near the cavity. The maximum displacement was 25.1 mm, the maximum compressive stress was 13.2 MPa, and the maximum tensile stress was 1.32 MPa. The displacement value was large and small localized tensile stress occurred in the plastic zone of the side wall and the bottom of the arch. Combined with the specific working conditions and measured geostress data, the rockburst analysis was carried out by the strength theory method, no rockburst occurred by the Russenes rockburst discriminant, and the jointed rock mass was in a stable state. However, with the development of joint fissures, the side wall and the arch bottom were prone to damage. It is recommended to use 2.5 m anchors for reinforcement. The simulation results are consistent with the measured data, and the research results can provide reference for engineering constructions.