The invention discloses a single-phase earth fault locating method of a power distribution network. The method comprises the following steps that (1) power distribution network fault indicators are mounted on all nodes and branches of the power distribution network, and three power distribution network fault indicators which are located on the same circuit and different in phase are used for comparing three-phase transient current information in real time to judge if faults happen; (2) fault information of all circuits is sent to a monitoring center to judge fault places. The method is simple and can be used for quickly judging fault positions.