Abstract: The paper aims to improve the freeze injury weather warning and disaster prevention level during apple flowering period. Based on the 5 freezing injury weather processes during apple flowering period in Yan’an since 2001, the authors analyzed the temperature, flower freezing rate and apple yield. The results showed that: the freeze injury during apple flowering period in Yan’an had a tendency of advanced date and aggravating influence; the severe cold injury year had the characteristics of earlier first day passed 0℃, obviously high temperature in March, and high accumulated temperature; the indicators of the formation of freeze injury during different phenological phases were different, the whole inflorescence was frozen in the central flower opening period and inflorescence separation period; a few central flowers were frozen when the extreme minimum temperature was -3℃; mild freeze and moderate freeze happened with the lowest temperature ≤-4℃ and ≤-5℃, respectively; at the full-bloom stage, the mild freeze occurred when the temperature dropped to - 3℃; moderate freeze occurred at -4℃ and the severe freeze occurred below -5℃. In the future, the prediction and impact assessment of freeze injury weather during the apple flowering period should not only consider the minimum temperature in the process of freeze injury, but also focus on the phenomenon of the first day passed 0℃, the temperature in March and the active accumulated temperature, and whether the temperature at the early stage is abnormally high.