A kind of apple quality grading system is designed based on motion controller and machine vision system, the system includes the detection module, image acquisition and processing module motion control module and execution module and other components. The operation is simple and accuracy is high, and it can realize the automation of apple quality grading, improve the labor efficiency. The non-contact structure is applied, the structure can overcome the previous mechanical damage caused by the contact of apple. It can ensure the quality after the apple classification. Research shows that this system is high reliability, good openness, grading error less than 3%, the production efficiency of 2～5 t/h. It can meet the requirements of the apple quality grading.