Through the numerical simulation in this paper,the influences of mining coal sea ms with different dip angles on the overburden failure and the development law of water-flow fractured zone was analyzed. The analysis on the displacement conto ur lines showed that with the seam dip angle increasing,the subsidence displacem ent was increasing gradually.The analysis on the stress diagrams showed with the increase in dip angle of coal seam,the thickness of the water-flow fractured zo ne also increased in a certain degree.These conclusions provided a theoretic bas is for engineering practice and safety of mining.