The invention provides a single-phase earth fault line selection method of a power grid with a neutral point earthed via an arc suppression coil, a device and a readable storage medium. The method comprises the steps of: monitoring a zero sequence voltage U0 of a power distribution network in real time, and judging whether the zero sequence voltage of the system is greater than 0.15 times of a busrated voltage UN; if so, starting a line selection apparatus to record the zero sequence current data of the first 1/4 power frequency period after a fault; performing frequency distribution processing on the zero sequence current data of various collected lines; and calculating frequency distribution values of the various lines according to data obtained by frequency distribution, and selectinga fault line according to the frequency distribution values. According to the single-phase earth fault line selection method provided by the invention, the fault line selection is performed by using the frequency distribution theory, and the original recorded data of the zero sequence current are directly used, so that the calculated amount is relatively small, and the speed of line selection is improved. According to the single-phase earth fault line selection method provided by the invention, the line corresponding to the minimum frequency distribution value is the fault line, the fault criterion is simple, and the fault line can be selected accurately and efficiently .