For the mining of the steeply inclined single thick coal seam, the horizontal stratification or beveled stratification is usually used, and the determination of the self-protective range under the influence of mining is the key to determine the measures of the regional outburst prevention. Taking Nanyangmiao Coal Mine in Hunan Province as an example, a number of studies, such as the industrial analysis of coal mining face and the observation of residual gas parameters, UDEC numerical simulation and data test, were carried out. The experiment results show that the stratification is equivalent to the exploitation of the protective layer after used horizontal stratification or beveled stratification method, and the lower part 1-2 layers are protected within the protected zone, which greatly simplifies outburst prevention engineering. The results provide a theoretical basis for the development of outburst prevention measures in steeply inclined coal seam, and it is of great practical significance for the safe production of the steeply inclined coal seam.