In order to solve the problem of low accuracy of high-resistance grounding fault line selection in low-current grounding systems, from the perspective of actively regulating the neutral point voltage, a multi-criteria grounding fault line selection method based on zero-sequence current variation is proposed. The grounding gear is evenly set on the system side of the special grounding transformer, the size of the grounding gear is flexibly adjusted, and the difference in the increase or decrease of the zero sequence current of each feeder is used for line selection. In the case of a large transition resistance, the non-linear distortion degree of the zero-sequence current of each feeder is used to assist line selection. Simulation results show that this method can effectively identify tens of thousands of ohms of ground fault feeders, and effectively improve the accuracy of high-resistance fault line selection in small-current grounded systems.