Abstract: F5 thrust a coal mine based on the actual geological data, by using numerical simulation software FLAC3D, the upper and lower two sets of F5 thrust face stope stress evolution rule of the fault zone and in turn fault activation law study, reveals the fault fracture zone in the process of working face mining width and the relationship between the reverse fault activation. Research shows that because the fault fracture zone has the larger deformation buffering capacity and the secondary stress generated by the absorption of mining, makes it hard for stress transfer across the fault fracture zone to more forward propagation, surrounding rock stress peak area is limited in the working face of coal wall and fault fracture zone on one side of the damage zone boundary between coal pillar, so the footwall mining working face, the working face advance to 210 m location, fault zone of the normal stress appears to slow down, slightly elevated phenomenon; Two sets of coal seam mining, the normal stress of fault zones, the two sets slippage and pore pressure of surrounding rock is proportional to the width of fracture zone, namely, the greater the fault fracture zone width in mining under the influence of the activation, so in practice need to be targeted prevention and control measures.