The invention discloses a distance measuring method used for measuring a position of a fault point in single-phase grounding, of a low-current grounding system. The method comprises the following steps of: (102) setting a measuring point on an outgoing line of the low-current grounding system and synchronously collecting current traveling waves in real time, wherein when the outgoing line is in single-phase grounding, the current traveling waves comprise a fault initial traveling wave transmitted through a lead with leads and a fault initial traveling wave transmitted through a lead with the ground; and (104) obtaining a distance from the measuring point to the fault point according to the formula of x=v1*v2*delta t/(v1-v2), wherein the delta t is the difference of the time of the fault initial traveling wave transmitted through a lead with leads on arriving at the measuring point and the time of the fault initial traveling wave transmitted through a lead with the ground on arriving at the measuring point, v1 is the wave speed of the current traveling wave transmitted through a lead with leads, v2 is the wave speed of the current traveling wave transmitted through a lead with the ground, and x is the distance between the measuring point and the fault point. The invention also discloses a distance measuring device. According to the invention, the position of the fault point in the single-phase grounding can be effectively detected.