The parallel compensation unit of traditional unified power quality conditioner （UPQC） has the problems of low signal acquisition accuracy and phase-to-phase coupling of control method. Aiming at the problems, the compensation signal detection method based on FUZZY-PID control and the current hysteresis optimal vector control method were used for parallel compensation unit. These methods can improve the detection accuracy through saving vector transformation and low-pass filter, resolve the phases coupling problem with coordinate transformation, and effectively improve the real-time performance of control and the accuracy of compensation. Finally, the feasibility and validity of the method were verified through simulation analysis and experiments.