4u series harvester of yams are suitable for potatoes, sweet potatoes. Garlic and other root crops, it is composed of components such as cutting seeding organization, field wheels, girders, excavating, a shovel, transporting chains, choosing sieve, they can integraly complete the working procedures such as harvesting, excavating, choosing, the series include the middle drive transmission and the left-side drive transmission for different types of tractors.