The invention provides a method and a device for monitoring late frost damage to crops based on remote sensing data. A monitoring area is gridded. For each grid point, the meteorological data of a meteorological station in the crop growth period is acquired on one hand, and on the other hand, the meteorological data in the remote sensing data in the crop growth period is extracted. The two types of meteorological data are assimilated to obtain assimilated meteorological data. Based on the assimilated meteorological data, the growth of crops on the current day is determined, and the biologicalcharacteristics of the crop canopy are determined. The temperature data of the crop canopy on the current day is determined according to the biological characteristics of the crop canopy and the meteorological data on the current day. The late frost damage area on the current day is determined according to the temperature data of the crop canopy on the current day. Therefore, remote sensing data and ground real-time monitoring data are combined in the monitoring process of late frost damage, the shortcoming of the method relying on ground real-time monitoring data only is overcome, and the monitoring precision of late frost damage is improved.