Abstract: In order to study the layout of the working face along the fault, the impact hazard of the mining space under different coal pillar width conditions. FLAC^3D numerical simulation method was used to study the stress, stability, normal fault activation and elastic energy spatial distribution of coal pillars with different widths. The results show that when the size of the fault pillar is small, the plastic failure occurs in the coal pillar of the goaf, and the fault slip extends from the basic top position to the fault plane of the high rock formation, and the fault slip is large. The mining stress concentration and elastic energy accumulation area is located in front of the fault side working face. When the fault pillar is large in size, the coal pillar can effectively control the fault slip at the basic top position, and only a small amount of fault slips at the high level rock fault. The concentration degree of mining stress and elastic energy density in front of side face are significantly reduced. Therefore, the plastic failure of fault pillars should be avoided when the size of fault pillars is determined.