Abstract: In the fruits and vegetables puffing process， there are interference and lag problems in the temperature of the heating tank. The interference and hysteresis caused the decline in quality of fruits and vegetables in extrusion machine temperature control system. This essay presented the quadratic performance index control method， which was proposed for parameter adjustment single neuron SNPID， and SNPID controller were designed by S7-300 PLC as the hardware carrier. The design of the controller improved the fruits and vegetables puffing temperature control system performance effectively， and advanced the system response speed， control precision and stability.

Key words: fruits and vegetables puffing, temperature control, SNPID, S7-300 PLC