Locating high-resistance grounding faults poses a tough and challenging problem for the safety of DC railway systems. High-resistance grounding fault current isn t sufficient to trigger switches, which may expand the accident or turn into potential hazards. In order to overcome the limits of the existing methods (such as signal injecting method, resistance method and so), developing a novel fault approach by using both the feeding current and voltage to detect and locate the high-resistance grounding fault in DC railway traction system is necessary. The simulation results prove that the exact fault location can be accurately predicted in this way. Through comparison of several different analysis methods, this paper concludes that with the digital signal processing the location can be executed more precisely. Extensive simulations with diverse fault conditions are performed to verify the means.