With the widespread use of large-capacity power electronic devices, there are too much harmonic current and harmonic voltage in power system at the same time. The active power filter (APF) or hybrid active power filter (HAPF) can only eliminate harmonic current or harmonic voltage, and possibility resonance. To eliminate harmonic current and harmonic voltage in power system simultaneously and enhance the capacity, the paper presents a hybrid unified power quality conditioner (HUPQC). Compared with UPQC, the HUPQC is made up of a hybrid series active power filter (the series device) and a shunt active power filter (the shunt device). The shunt device employs an injection circuit to lower the capacity of the active part to fit high-voltage power system. Designed reasonably, and controlled with composite control method, the HUPQC can filter the harmonic current and harmonic voltage effectively at the same time. At the end of this paper, the simulation and experiment results improve that the HUPQC can prove the power quality greatly and achieve satisfactory effect. Keywords-harmonic current; harmonic voltage; UPQC;HUPQC; active power filter; power quality I.