Abstract: In order to study the major influence factors of support stability under the condition of large inclination angle, this paper has setted up the horizontal and longitudinal model by theory methods and acquired influence factors about support stability, including support weight, working pressure, base width, lemniscates links, s tabilizing interval.Based on the methods, obtaining the following conclusions for Shicaocun coal mine:critical angle of slipping of support is 26°42°, critical angle of slopi ng of support is 31050°, stabilizing interval is 270 mm.According to the results, the measures of the powered support stability were proposed from two aspects of mining technique and the powered support design.