The invention discloses a distribution network transient state fault line selection method for grounding fault transfer control. When a neutral point non-effective grounding distribution network adopting grounding fault transfer control generates a transient single-phase arc light grounding fault, grounding fault transfer is utilized to control the characteristic difference of fault transient currents in the specific fault grounding and fault phase bus active grounding processes, that is, the directions of fault line transient zero-mode currents in the two-time grounding processes are opposite, the directions of non-fault line transient zero-mode currents in the two-time grounding processes are the same, and line selection criteria are constructed. The zero-mode currents, with the 1/4 power frequency period, after two-time grounding of all feeder lines are subjected to wavelet packet decomposition correspondingly, the characteristic frequency band is determined through wavelet energy,multi-scale reconstruction is conducted to extract the transient zero-mode currents, and the correlation coefficient polarity between reconstructed data is utilized to achieve fault line selection. The distribution network transient state fault line selection method effectively improves the reliability and accuracy of fault line selection of the non-effective grounding distribution network, and inaddition, fault line selection can be completed only through fault line information.