The underground power transmission mode uses cable tunnels as carriers, gradually replacing overhead lines above ground to dominate power distribution networks. During the operation of cable tunnels, real-time monitoring of cable operating conditions is necessary. Aiming at cable tunnels with weak GPS signals and lacking basic communication network infrastructure, this paper designs a mobile detection system with dual self-organizing network functions of positioning and communication. Combining the environment of cable tunnels, this system realizes cable tunnel exploration and real-time video transmission by robots in an optimal formation based on a swarm control algorithm, meeting the needs of emergency environmental monitoring in cable tunnels.