Abstract: In view of problem that it is difficult to realize fault positioning by use of artificial patrol after single-phase grounding fault occurred in distribution network, a fault section positioning and ranging method of distribution network based on distributed parameter model was proposed. In the method, fault section is chosen through analyzing and calculating of fault information and date uploaded by feeder terminal unit of line, and fault distance is obtained by online calculating distributed parameters of the section line. The simulation results show that the method is less affected by factors of transition resistance and fault location, which can effectively realize fault line selection and section positioning within 1% ranging error.