Abstract: As the impedance topology of low-voltage distribution network is not clear,an online identification method of constructing impedance topology model of low-voltage distribution network based on AMI measurement information is proposed in this paper. First,using the voltage data of each power user provided by AMI,and according to the voltage correlation of each load node and the voltage distribution characteristics of the radiant network node,and through the Kmeans clustering algorithm and the Pearson voltage correlation coefficient analysis principle, we revise the low-voltage distribution network topology model. Second,based on the sequence data collected by the smart meter under the same phase in the revised topology of the station area, the optimization problem model is built by calculating the phase voltages of all users in the same phase. The variance of the phase voltage matrix calculated from different meter data in the time series is minimized to obtain the line impedance parameters of the distribution network,thereby the accurate modeling of the distribution network can be realized. Finally, a practical example is used to verify the feasibility and effectiveness of the method.