The method discloses a fault line selection method based on a phase current transient characteristic. The method comprises the following steps of S1, continuously measuring a distribution line outlet zero sequence voltage value and determining whether a power distribution network generates a grounding fault; S2, processing collected phase current data, extracting a transient phase-current sudden-change amount of each line, and carrying out interphase pairwise correlation analysis so as to obtain an interphase minimum correlation coefficient rhok min; S3, carrying out spectral analysis on each line fault phase current and calculating a gravity frequency fkg; S4, carrying out normalization processing on a fault characteristic quantity and acquiring normalization values, establishing a two-dimensional coordinate system based on the normalization values, and determining each line fault characteristic coordinate point; and calculating a fault characteristic distance dk between each line fault characteristic coordinate point and a reference point (0, 0) so as to determine a bus fault. The method possesses advantages that a principle is simple; practicality is high; an anti-interference capability is good; accuracy is high and so on.