Abstract: In order to research the interaction effect between the working face and faults, we use FLAC^3D software to simulate the effect of seam excavation on fault and the distribution laws of rock pressure under faults and without faults. Research show that abutment pressure around faults sharply reduced then gradually increased; and it returned to normal distribution away from the fault. The existence of faults intensified roof convergence. Stress criterion is used to determine the height of water flowing fractured zone to determine the reasonable size of fault coal pillar.