In order to measuring arc suppression coil grounding system line -to-ground parameters conveniently and simply, anew tuning method of arc suppression coil based on the increment of zero-sequence voltage amplitudeis proposed. In this method，thedistribution network neutral point will be added the arc suppression coil and resistor, first measure the amplitude of the zero sequence voltage before incorporated resistance;afterincorporated resistance , measure the amplitude of the zero sequence voltage again, then repeatedly adjust the arc suppression coil inductance value, furthermeasure and record the amplitude of the zero sequence voltage.Rely on the recorded measured values, it can be substituted into the equation to obtain the total capacitance and resistance to line -to-ground. Finally, Build a model using Matlab simulation experiment and this method needn’t measure zero- sequence voltage phase .It has the advantages of simple operation, high accuracy and so on. It is very significant for the tuning of the arc suppression coil.