In order to reduce the coal mine large reactive power of electrical equipment, further reduce the harm of harmonic in power grid, the practice and research showed that mine SVG reactive compensation power saving technology and electricity-saving rebuilding had good effect on reducing harmonic current, harmonic voltage that produced in mechanized working face large use of  inverter, rectifier equipment and power electronic equipment running, which fully compensated reactive power consumption equipment, greatly improved the power factor of the equipment and ensured the efficient economic operation.