Abstract: The mine distribution network is a single-ended power supply system,its neutral point is ungrounding or grounding by arc suppression coil.When single-phase grounding fault happened,fault current is weak,so it is very hard to locate fault position.To solve the problem,the paper proposed a single-ended traveling wave fault ranging method based on difference of wave velocity between zero mode component and aerial mode component of traveling wave.It analyzed theory of traveling wave ranging in details,expounded measuring method for wave velocity of aerial mode and zero mode.By the simulation of ideal condition and existence of transitional resistance confirmed effectiveness and feasibility of the method.