The invention discloses a control method for a quality control system of micro source internetworking electric energy. A primary side of the coupling voltage transformer on a serial active power filter side of a UPQC (unified power quality controller) is connected with a larger current-limiting inductor in parallel, and a direct-current large-capacitance side of the UPQC is connected with a photovoltaic generating power supply in parallel. Due to effects of cooperative control, the photovoltaic power supply is internetworked for power generation during normal operation, active power is provided for a power grid by the parallel active power filter of the UPQC, and the harmonic current from a load side and the voltage fluctuation and harmonic voltage from the power grid side are governed and compensated by the UPQC. In the case of short-circuiting failure on the load side, the main circuit of the UPQC stops operating, a secondary side of the coupling voltage transformer is subjected to high impedance, and the current can be limited by the parallel current-limiting large inductor. By adopting the method, the functions of failure current limitation, harmonic treatment, voltage support, photovoltaic power generation and the like can be realized during micro grid internetworking operation, and the optimized protection and operation of the quality of electric energy in micro grid internetworking can also be realized.