In order to realize the automatic detection of surface defects of notebook computers shell in industrial production, a PLC intelligent control system based on visual inspection was designed to effectively improve the production automation degree. Based on the original automatic production line, the whole device was reformed and designed by using SolidWorks software, including visual inspection, defective product removal, material disk storage and other devices. Through the visual inspection technology to effectively identify the notebook computers shell defects, combined with PLC control technology, pneumatic and sensor technology, the automatic identification and packaging of finished products and defective products were realized to reduce production costs and improve production efficiency. The modified device has broad market demand and industrial application prospect.