The invention relates to a wireless communication system of an electric transmission line on-line monitoring system. The wireless communication system is based on a ZIGBEE protocol. The system comprises a wireless terminal module arranged on an electric transmission line master station and a wireless router module arranged on an electric transmission line pole tower. The wireless terminal module is used for receiving data of the wireless router module and issuing instruction data of the master station to the wireless router module at the same time. The wireless router module is used for achieving the routing function of wireless signals and completing information reporting and instruction receiving and executing tasks of the electric transmission line at the same time. By the adoption of the system, high-reliability and high-safety wireless real-time data transmission can be achieved conveniently, the advantages of being good in real-time performance, high in safety and flexible in networking are achieved, and space and cost can be effectively saved.