This paper describes the three-phase three-wire system of unified power quality conditioner (UPQC) topology, and combines UPQC compensation thought, using dq0 transformation method based on instantaneous reactive power theory to detect voltage and current compensation signal. The paper simulates it, validates the superiority of the detection method. At last, it studies its control strategy, through the UPQC system simulation validating the correctness of detect and control method.