Two stages series active power filter are used to harmonic suppression and reactive power compensation in anechoic chamber. The dry-type iron core reactor is shunt between the filter and the load power supply terminal. Dry iron core reactor is mainly used for the inhibition of 10kHz and above high-frequency interference. It can effectively suppress high order harmonic, limit switch flow and operating over-voltage, improve power factor and voltage waveform of the system withoutSaffectingSthe filter performance of theSseries passive power filter. It playsSan importantSroleSinSthe safe operation of power capacitor and power equipment.SParallel dry iron core reactor not onlySsolveSthe problem of voltage variation of various reactor load at the entrance of the load, but also improve the accuracy and reliability of the performance measurement in electromagnetic compatibility testing.