Low-voltage distribution lines have been lacking monitoring for a long time.With the large-scale access of DERs,it is necessary to establish a low-voltage distribution line monitoring system to ensure electrical safety and optimize electricity services.The low-voltage distribution lines monitoring system based on the Internet of Things technology contains a large number of low-voltage monitoring terminals,and different manufacturers and different types of terminal equipment need to solve the problem of information interaction.Based on the analysis of the communication requirements of the monitoring function of low-voltage distribution lines,the information models of various functions and terminal equipment are researched based on IEC 61850,and develops low-voltage distribution lines monitoring terminals,smart gateway and smart management module based on the IEC 61850 information model.The developed low-voltage distribution line monitoring system has been applied in Jiangmen city,which realizes the monitoring of low-voltage lines and DERs,and improves the electrical safety and electricity service of low-voltage distribution network.