The invention discloses a method for positioning a power distribution network single-phase earth fault single-ended section. The method comprises the following steps: firstly, collecting three-phase fault current traveling waves on a 10kv outgoing line in a power substation; secondly, carrying out phase-mode transformation to obtain line-mode and zero-mode traveling waves; then, carrying out HHT conversion on the line-mode traveling waves, and calibrating the arrival moments of line-mode traveling wave initial wave heads and a plurality of previous reflected wave heads; and finally, carrying out fault section positioning by adopting the positioning method based on distribution network topology provided by the invention. According to the method, the section positioning for power distribution network single-phase earth faults is realized just by using single-ended three-phase current traveling wave information.