Abstract: For problems of large voltage fluctuation, low power factor, large line loss, difficult starting of device and so on of power supply system in working face, the paper proposed a technical route of var compensation which takes SVG as a core, and introduced design scheme of mine-used 3.3 kV static var compensator based on SVG. The industrial test result showed that the compensator has performances of quick response speed and smooth and correct compensation, which improves power factor of power device in starting and running process, shortens starting time, improves stability of starting and running voltages, restrains harmonic wave efficiently, and has obvious energy-saving effect.