In view of the low pressure area long running power lines anomalies such as aging, a method based on the loop impedance change of low voltage power lines health state evaluation is proposed.By collecting the power data automatically by the metering device node voltage and current data, and calculate the line loop impedance according to the sudden change of voltage and current, so as to obtain the loop impedance characteristics of the corresponding line. After corresponding data processing, the impedance change curve is drawn, and the health status of the line is evaluated by the change of the circuit impedance. Finally, an example is given to verify the effectiveness of the proposed method.