In order to improve the automation level in the production process, a set of automatic sorting system with feeding,transmission,testing,sorting and packaging functions, compatible with various products was designed by combining machine vision with Mitsubishi FX series PLC. Through the realization of automatic sorting of small workpieces, the production efficiency of small workpieces sorting is improved, the production quality is guaranteed, the personnel investment is reduced, which produce good economic benefit. The system provides reference for improving the sorting of same type of small workpieces.