Abstract: According to the specific geological conditions of fault tectonic, based on similar simulation, numerical calculation and the combination of industrial field tests, and through similar simulation test, the paper obtains faults slip and activation occur when distance from working face 28 m under the influence of mining, the pro cess is divided into instability, slip and activation; fault prone areas are broken slip instability border zone, the immediate roof area and roof area; fault slip instability ex acerbated tunnel surrounding rock deformation, especially in the first activation of the fault slip, the floor heave deformation more serious, or even the impact of roadwa y floor.By numerical analysis, the easy transfer of surrounding rock footwall rock stress on the fault than the plate, easy to accumulate and release energy; floor heave about 1.8 times in the footwall; it is pointed out that the deformation of the floor heave is the most serious in the process of fault slip and activation, the right shift is nea r, the roof subsidence and the left shift are smaller.Finally, it is proposed mechanism of roadway pressure bump induced by fault slip and activation.