In the active distribution network, different choices of the DG neutral point grounding method will have different effects on the original fault electrical quantity. From the angle analysis of the small current grounding system and the DG neutral point grounding method, it can be seen that the DG adopts the neutral point ungrounding method, and the conclusion that the transient zero sequence current is not affected by the DG access is obtained. On the basis of this, in order to solve the problem that the fault information is not fully utilized and the single criterion has the location blind zone, a fault location method based on the generalized S-transformation multi-dimensional criterion is proposed to perform the generalized S transform on the transient zero-sequence current signal. The main resonance frequency and the transient energy feature quantity are extracted by using the amplitude matrix fault information. It is also proposed to construct the statistical polarity feature quantity by using the often neglected phase angle matrix, and a complete multi-dimensional fault section criterion is constructed. By comparing the fault feature quantities of the two detection points in turn, if the difference is large, it is determined as the fault section. Theoretical analysis and simulation results show that the method can locate fault sections effectively and accurately, and has strong applicability.