Firstly, this paper establishes the assessment indicator system for the earthquake prevention and disaster reduction capability of county-level administrative units in Gansu, and formulates three criteria, ten indicators and fifteen variables centered on one target. Then, the analytic hierarchy process is applied to determine the indicator weights, and the environmental supporting capability, infrastructure supporting capability and resource supporting capability of different counties in Gansu in the handling of earthquake disasters are calculated to obtain the assessment figure for the earthquake prevention and disaster reduction capability of county-level administrative units in Gansu. The research results indicate that Anning District of Lanzhou has the strongest earthquake prevention and disaster reduction capability while Zhouqu County possesses the weakest earthquake prevention and disaster reduction capability; the overall earthquake prevention and disaster reduction capability of northwestern and northeastern regions in Gansu is higher, in which the earthquake prevention and disaster reduction capability of Aksay-Subei District, Jinchuan District, Xifeng District, Linxia City District and Lanzhou City District is particularly prominent; the earthquake prevention and disaster reduction capability of Sunan-Tianzhu District and Gannan-Longnan District is relatively weaker; the geographical environment has a great impact on the earthquake prevention and disaster reduction capability, which is demonstrated as that the earthquake prevention and disaster reduction capability of regions with violent tectonic activities and dramatic topographic inequality tend to be weak; the whole province should improve the construction of infrastructure and fundamental resources in order to compensate for the insufficiency in environmental supporting capability. In addition, the expert scoring method is adopted in the determination of indicator weights, which is subject to high subjectivity; considering that some data are missing and the influential indicators are not considered comprehensively, the assessment indicator system requires further improvement.