The 4U-90 sweet potato harvester, based on the original ordinary harvester, uses a movable shovel instead of a fixed shovel: reducing resistance, preventing soil blockage, and reducing the power requirement of the tractor. The grass cutting disc can chop up 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, harvesting with vines, light and smooth operation without vibration, no grass clogging, no soil clods, simple structure, and long service life. It is a national patented product and a domestic innovation.