A portable Chinese yam harvesting machine comprises a rack, wherein a power part, a power bracket and a ground tilling part are arranged on the rack; the power part is arranged on the power bracket; the ground tilling part comprises an outer sleeve and an inner sleeve detachably arranged in the outer sleeve; the power part provides power for the rotating of the outer sleeve, and a spiral auger soil discharging device is arranged on the outer surface of the outer sleeve; and saw teeth are distributed at the bottom end of the inner sleeve, and the outer surfaces of the saw teeth of the inner sleeve are flush with the outer surface of the outer sleeve. The portable Chinese yam harvesting machine is suitable for on-ridge operation. The outer sleeve and the inner sleeve can directly carry out soil discharging operation above Chinese yams, and workers later take out the Chinese yams. During harvesting, the precision is high, the damage rate of the Chinese yams is low, and the economical benefit of Chinese yam growers can be improved. At the same time, the device is small in size, flexible in use and simple in operation, can save labor and material cost for individual Chinese yam growers with small area, and has high practicability and suitability.