At present, the domestic most economical plastic extruder temperature control system widely used separation instrument control scheme and two kinds of PLC centralized control scheme. For the separation of instrument control scheme, although has the advantage of low price, but on the control function is limited by many, mainly reflected in the control of the separation unit independently, comprehensive control, the entire system cannot be implemented more than the use of temperature control table, on the one hand, make the temperature control circuit structure is complex, failure rate increases, on the other hand, due to the temperature control table for intermittent temperature control mode, more so caused by the heating zone temperature fluctuation is bigger, affect the quality of the plastic products processing. For PLC centralized control scheme, although can implement integrated control of the whole system, but will write more loop PID temperature control algorithm is difficult