Abstract: This paper takes the middle Aishan reverse fault of Pingdingshan No.11 Mine as an example, and studies the aspects of ground stress distribution in range of fault, structure coal development and gas abnormal distribution, and determines the scope of the gas anomaly zones in fault zone, then to provide basic data for prevention and control measures of gas. The results show that the hanging wall of Aishan fault is the active plate which is sheared and damaged seriously, the breaking degree of coal and gas enrichment degree are better than the footwall; the fault pinchout end is impacted by the disturbance of adjacent faults and forms an abnormal stress concentration area, the gas within 60 m of the abnormal area is greater than the control area of other parts of fault. The delineation of gas abnormal area in fault zone improves the prediction efficiency of outburst prevention in working face of mining area.