The late frost event on 15 May 2016 is the most serious meteorological disaster in the eastern Hexi Corridor since 2004 In this paper, by using the MICAPS real time meteorological data, physical quantity field and hourly observation data of regional stations, the causes of this freezing process are analyzed. The results show that the main causes of the disaster include the strong cold air, rapidly alternating cold air and warm air, and rapidly surface temperature rise resulted from strong warm advection, as well as the high temperature burn of crops. On the basis of the analysis of the characteristics of temperature and surface temperature, the temporal and spatial variation of regional temperature, and the evolution of the hourly temperature, this paper also analyzes the causes of the damage and further reveals the disaster characteristics from the three aspects of low temperature duration, relative humidity, high temperature burns, and the findings provide a positive and effective scientific basis for regional defense of late frosts.