Abstract: Fault is a geological structure with potential vulnerability in the working face and its vicinity, and it is also a geological factor that can not be ignored due to its affect on the safe mining of coal mines.In order to study the destabilizing failure of the surrounding rock caused by fault activation under the influence of mining, the deformation and failure process of the surrounding rock in the vicinity of the fault-affected area is studied by using actual engineering and numerical simulation analysis.Based on the discrete element 3DEC numerical simulation software, the destabilization and rupture model of surrounding rock induced by fault activation under mining conditions was established, and the disturbing stress and roof delamination monitoring in the area affected by fault activation were analyzed.The results show that the mining stress gradually increases with the continuous advancement of the coal mining face; the relationship curve between mining and roof displacement of the coal seam near the fault is jagged, which indicates that the surrounding rock in the fault activation-affected area is in the state of superposition of static and dynamic loads; the stress and displacement of the surrounding rock near the fault increase with the advancement of the coal mining face, and the closer to the fault face, the displacement gradually goes back to zero, and the stress is in the state of lower level.