In this paper， we introduce a food production and packaging system. This system includes many processes, namely, mixing, blending, molding, drying, packaging, and relates to multiple devices. To ensure the quality of food production and packaging, it needs coordination of all procedures and controls based on process requirements to achieve different objectives, so we use PLC centralized control in the food production and packaging system. According to the control object, we allocated the PLC address and choose the PLC of Siemens S7-200. On the basis of control tasks, we designed a control flowchart and programmed for PLC control system of Siemens S7-200 using STEP7-MICRO/WIN programming software .The practical applications have proved the good results.