Abstract: In order to study the influence of fault band on coal seam mining,taking the fault Sun stratigraphy of the East Second Mining Area of Longdong Coal Mine as the prototype,we simulated coal seam excavation according to the geological characteristics of mining area by using numerical model which was established on the basis of FLAC^3D.According to the numerical simulation result,we judged the plastic property deformation of the goaf and the stress variation in the roof of the coal seam under different fault coal pillars.Only in this way can the fault coal pillar be set reasonably.The research showed that the damage of the roof and floor of the goaf was becoming more and more serious with the working face of coal mining push forward.When the coal seam mining 95 m,the roof and floor of the goaf was seriously damaged and the formation adjacent to the fault was being destroyed,leading the damaged faults to become geological faults,and causing the occurrence of coal seam water inrush events.Meanwhile,the stress characteristics of the coal seam roof were analyzed when the coal seam mining 95 m,and came to the conclusion that the width of the fault pillars should be rationally set as 55 m.