Abstract: In order to accurately determine the reasonable sealing hole depth of extraction borehole, the article analyzed the reasonable range of sealing hole from the perspective of the roadway "three zones", and discussed the influence factors of drilling cuttings volume in terms of the drilling cuttings index theory. According to the relationship of drilling cuttings and ground stress, based on the site practices in Huangyanhui Mine, with the calculation on the variation law of drilling cuttings, and combined with numerical simulation software of FLAC^3D, the article determined the reasonable sealing hole depth was 8.5 to 13 m in the buried depth of experimental zone coal seam, which proved the accuracy by field test.