Abstract: The sweet potato slicer is an agricultural product processing equipment, mainly used in the production of sweet potato chips. At present, the existence and widespread use of the hand-style sweet potato slicer. Its structure is extremely simple, the main components for the knife and the handle plate. Role in human, by turning the handle to power the cutter reached. This piece of the low rate of mechanical, and laborious. The design for the hand-style sweet potato slicer improvement: the use of the dynamic part of the electromagnetic motor drive, and then through a small pulley and pulley power passed to a knife slicing disk, slice final; and the use of motor speed JD controller in order to achieve automatic control of sweet potato slicer design. Keywords: sweet potato; slicer; motor; Pulley; JD controller