This paper presents an accurate fault location method for low voltage（LV）power cable with steel armor.The proposed method uses the characteristics of the cable steel armor winding，applies the high-voltage pulse between the fault cable wire and steel armor to produce flashover discharge and detects the three-dimensional transient magnetic field signal around the cable.Compared with the synthetic magnetic signal generated by the discharge current in the cable wire and the steel armor before and after the point of failure，the method is able to determine the exact location of the cable fault point.This paper analyzes and calculates the magnetic field generated by the discharge current flowing through the steel armor flashover.The experiment results have verified the feasibility and effectiveness of the proposed method.Based on the principle of this method，a prototype was developed and applied to the actual locating of the cable fault.The proposed method is a non-contact cable fault locating method that can be used not only for direct-buried cable laying but also for cable laying as pipe laying or trench laying.