The access of arc-suppression coilto the distribution network weakens greatly the feature of single-phase earthing fault and causes difficulty to select line accurately. It is found by setting the transient zero-zero network of single phase earthing fault of resonant earthing system that the transient zero-sequence current waveform of all healthy lines are highly identical

while the difference between the transient zerosequence current of the faulty line and that of healthy line is remarkable. The fault line selection proposal based on the cross-correlation coefficient of transient zero sequence current waveform is constructed. It is shown by the simulation resultthat the calculation result of the cross-correlation coefficient of the transient zero-sequence current waveform between the healthy lines is close to 1;and the calculation result of the relationship between the zero-sequence current waveforms between the healthy line and the fault line is close to-1. It is shown by the calculation result that the method can effectively identify faulty lines and have good applicability.