According to the three-phase unbalance, harmonics and reactive power of the distribution network caused by different time periods or different loads, the advanced control algorithm is used to separate the negative sequence, zero sequence, reactive power and harmonic components of the current. The power device IGBT makes the inverter send out the opposite compensation current to eliminate unbalance and compensate reactive power and harmonics. Through the orderly control of the intelligent coordination unit, the active device can quickly respond to the reactive power demand while the reactive power changes. After the capacitor is put in, the previously put active capacity is removed, and the active capacity is fully used to compensate for harmonics and non-power. At the same time, the balance current makes the device have the characteristics of fast response, which can meet the requirements of the occasions where the reactive power changes rapidly.