This paper analyses the fault gases of each segment of large faults in the northern fringe of Qinling Mountain, determines the segment order of strong earthquake risk: the earthquake risk is stronger in the Guide-Xunhua segment than that in the Lintong-Xianyang segment; the earthquake risk in the Qingshui segment is between above-mentioned two segments; and the earthquake risk is stronger in the Tianshui-Hezheng segment than that in the Meixian-Lantian segment. The authors further determine that the Guide-Xunhua segment and Qingshui area are strong earthquake risk areas, and in the Meixian-Lantian segment there will not occur any earthquake (M≥7).