LED streetlamp monitoring system is an application of PLC( power line communication) technology. 　A LED street network addressing algorithmis developed，which can be used in low voltage distribution network based on ACA( ant colony algorithm). Wepay focus on the objective function，the pheromone updating rule and state transition rule and search and other elements of the revision and improvement，it constructs not only the automatic routing model，but also a framework of automatic routing protocol. With this model，the low - voltage distribution network channel quality can be identified dynamically. Through the change of channel quality，routing power linecommunication network can complete the dynamic maintenance，so as to further realize the reliability of communication network. Finally，the practice and reliability of this method are verified by the simulation model of the channel and the assistance of the field test.