The 4U-90 potato harvester, based on the original ordinary harvester, uses a movable shovel instead of a fixed shovel to reduce resistance, prevent soil blockage, and reduce the power requirement of the tractor. The grass cutting disc can chop sweet potato vines and weeds in the field. It is highly effective, has good passability, and significantly improves harvesting efficiency. It features high harvesting efficiency, no skin damage, and the ability to harvest with vines.