In temperature and pressure reduction system

time-variation and nonlinearity exist in its tempera- ture PID control

so the satisfactory control effect is hard to obtained. In order to solve this problem

this paper combines the advantages of PID control and fuzzy control to deduce the control fuzzy rules table

membership func- tions and linguistic variables used for temperature and pressure reduction system control based on the identification and analysis of the characteristics of controlled object. The fuzzy PID controller is designed and its simulation analy- sis reference to the classical PID controller is done. The simulation curves show that the dynamic transition time and the steady-state error of the fuzzy PID controller in this paper are better than the classical PID controller. The con- trol performance of the fuzzy PID controller meets the temperature control requirements needed by the temperature and pressure reduction system control.