The work aims to design and research an automatic coin differentiating and wrapping machine in order to solve various kinds of problems concerning automatic sorting, classifying and packaging of coins. The coins were orderly loaded through centrifugal force and then classified in the negative classification method for differentiating. Next, coins were counted by photoelectricity, moved for positioning, piled for stacking, until they were wrapped finally. The key parts were analyzed in the finite element method. Based on the analysis results, the structure was optimized and the deformation was reduced. PLC control system was used to control the working process of the complete machine. In conclusion, the mechanical-electrical integration of the equipment and the adaptability and reliability of the complete machine are enhanced by using PLC control system.