Abstract: A fuzzy-immune-PID controller was designed based upon the principle of immune feedback control and fuzzy PID control with parameter self-tuning.The controller integrated fuzzy control,the rule of immune feedback control and PID control.The fuzzy-immune-PID controller was used in direct power control based on voltage orientation in 3-phase PWM rectifier to improve the performance of 3-phase PWM rectifier controlled by traditional PID controller.Test results showed that the fuzzy-immune-PID controller could achieve high power factor, low harmonic,good dynamic performance and possess better robust property to load-disturbance.