The present invention belongs to the power distribution fault detection technical field and relates to a power distribution network fault type identification method. Reports about diagnosis methods for identifying faults by using specific quantitative indexes according to arc characteristics of different fault types do not appear. The power distribution network fault type identification method includes the following steps that: the voltage and current waveforms of a fault line are obtained; the least squares method is utilized to calculate arc voltage Varc; the variance of a continuous single-phase grounding fault is obtained, so that the mean value Vzrc of the amplitude stabilization section of the arc voltage is obtained; and Vzrc is compared with a set threshold value Vset, so that the type of a power distribution network fault is identified. According to the power distribution network fault type identification method of the invention, corresponding arc voltage criteria are provided according to different fault types on the basis of the specific arc voltage calculation formulas of fault waveforms and the causes of the different fault types, so that the fault types can be identified. A new method is provided for power distribution network fault type identification.