In the background of wide distribution of overhead transmission network, difficult operation and maintenance and many disadvantages of regular maintenance, the author deeply analyzes the communication modes and their advantages and disadvantages of the transmission network digital monitoring system, and puts forward a new communication mode of hybrid ad hoc network, supplemented by optical fiber communication, WiFi and 4G communication. Type. This new communication mode can not only give full play to the advantages of the existing mature and rich optical fiber communication lines in the unsignal area overhead lines, but also give full play to the advantages of the flexible access of WiFi and 4G, so as to solve the difficulty of data transmission in the non signal area monitoring data, the non optical fiber connection entrance of the 4G signal unstable region and the difficulty of opening the fiber interface. Question. The popularization and application of this hybrid ad hoc network communication technology has important theoretical reference value for promoting the further application of the overhead transmission network monitoring system in the power grid, promoting the gradual realization of the state maintenance of the power grid and the modern management mode of digital intelligence.