The utility model provides a unified electric energy quality controller comprising a serial connection unit and a parallel connection unit. The serial connection unit comprises two serial connection converters and three transformers. The parallel connection unit comprises a parallel connection converter. Three single-phase output ends of an AC side of each of the serial connection converters are respectively connected with terminals of the three transformers. In-phase output ends of the two serial connection converters are connected with the same transformer. All the received voltages are serially connected with each single-phase feeder line of the three-phase feeder line after the coupling of the three transformers. A DC side of each of the two serial connection converters is connected with a DC side of each of the parallel connection converters, and the three single-phase output ends of AC sides of the parallel connection converters are respectively connected with each single-phase feeder line of the three-phase feeder line. The unified electric energy quality controller is advantageous in that the sub-module redundancy problem can be solved, and the voltage dip compensation capability and the working stability are high.