Abstract: Hazard assessment is a new research topic, especially for the perennial fruit crops, because the data of the actual investigation and observation is very little, many natural disaster mechanisms are still not clear, therefore, the evaluation is very difficult, risk assessment of meteorological disasters is still in the initial stage of exploration and research. Assessment of meteorological disasters based on pear yield loss can provide scientific basis for meteorological disaster risk assessment, prevention and mitigation of meteorological hazard on fruit tree production and formulating the relief measures. Using statistical methods and risk theory, the authors identified three different climate zones, including Weibei Dryland Mountain Area, Weihe river valley plain area and Guanshan Mountain Area in Tianshui, clarified effect of main agricultural meteorological disasters on pear yield formation and built a risk assessment model of agricultural meteorological disaster risk assessment based on the pear yield loss. As to the three different types of microclimate in Tianshui, major severe agricultural meteorological disasters on pear yield formation are: early spring drought in March, summer drought in July and freezing injury in April florescence. Assessment of disaster (including small disaster, secondary disaster, catastrophe and catastrophic disaster) marks 18 a as disaster year and evaluation of accuracy was 94%; among them, assessment accuracy of the secondary disaster and catastrophe reached 100%. The evaluation accuracy is high and the effect is ideal. Study of meteorological disaster assessment can provide reference for perennial fruit trees and have guiding significance for agricultural disaster prevention and mitigation.