The invention discloses a method for freeze drying barbary wolfberry fruit powder. The method includes the following steps: selecting, cleaning and draining barbary wolfberry fruits; crushing the barbary wolfberry fruits into small particles by using a crusher; evenly spreading the barbary wolfberry fruits on a tray, and putting the tray into a drying box of a freeze dryer, wherein the set freezing temperature is below -25 DEG C and the freezing speed is 0.50 DEG C/h; starting a vacuum pump, reducing the pressure in the chamber to 65Pa, and starting heating a heating plate; controlling the pressure variation not more than 150Pa and the temperature lower than -14 DEG C, and drying for 9-10 h; heating the drying box to a temperature of 20-70 DEG C and maintaining the temperature for 5-6 h; and crushing the barbary wolfberry fruit particles, and packaging the barbary wolfberry fruit powder. The method can make the dryer consume the lowest energy and ensure the quality, and the dried barbary wolfberry fruit powder is not prone to bonding.