Abstract: In order to solve the problem that single-phase grounding capacitance current of isolated neutral system could cause secondary disaster and equipment damage in distribution network and generate single-phase arc grounding over-voltage and ferromagnetic resonance over-voltage, the paper analyzed and evaluated testing data of capacitance current of distribution network of Renlou Coal Mine, established a treating scheme of capacitance current according to evaluating results, namely changing isolated neutral system to neutral grounding running mode by arc suppression coil, and gave concrete implementing scheme. The running result showed that the scheme greatly decreases rate of accidents of arc grounding over-voltage with high amplitude and restrains ferromagnetic resonance over-voltage, which was good for prolonging usage time of cable.