The invention discloses a power distribution network broken line identification method based on positive sequence current break comparison. The three-phase voltage of a bus and the three-phase current of each outgoing line are acquired at a transformer station, the break variable of the three-phase voltage amplitude and the amplitude of the three-phase current of each outgoing line are calculated based on the three-phase voltage and the three-phase current, the positive and negative zero sequence component of each outgoing line and the break variable of the positive sequence current are calculated, and the amplitudes of the positive sequence current break variables are compared, wherein the line with the largest break variable is the fault line. The power distribution network broken line identification method only uses the transformer station information and is not influenced by the grounding manner and the broken line position of the power distribution network neutral point, can reliably identify the nongrounding fault of the broken line and the grounding fault of the loading side of the broken line, thereby effectively improving the reliability of the power distribution network power supply.