Abstract: In our country, the straw mechanization processing level is low, using cost is high, which causes a serious waste of straw resources. In order to realize fully automated feed production and improve production efficiency, a feed production line control system based on Siemens S7-200 SMART PLC and Ethernet communication is designed. This paper focuses on the process design of wrapping production line, hardware system selection, control circuit design, software system I/O point allocation and control process design, and realizes the automatic ratio of straw raw materials, mixing and stirring, wrapping storage, field monitoring, fault alarm and other functions. The test results show that the production line can control the whole process of batching and production through the industrial computer or touch screen, which has a high degree of intellectualization and automation; and it is suitable for the feed production industry to meet the growing needs of feed consumption in domestic animal husbandry.