The national distribution network widely adopts the grounding operation mode of neutral point arc suppression coil. Due to the compensation effect of the arc suppression coil, the single-phase ground fault line selection method based on the steady-state signal basically fails. According to the differences in the amplitude, frequency distribution, and polarity of the transient zero-mode current of the fault line and the sound line in the amplitude, frequency distribution, and instantaneous mutation of the fault, MATLAB is used to build two resonance grounding systems of 10KV pure overhead line and cable hybrid line, and simulation research is carried out to verify the correctness of the method.