<p>To ensure the quality of information collection and transmission for fault localization in ultra-high voltage (UHV) dense transmission channels, a fault localization technique for UHV dense transmission channels is proposed. The routing of the wireless sensor network is constructed using the ECCTP routing algorithm. A path planning model that aims to maximize the amount of data collected per unit time is employed to plan the paths of mobile data collection nodes. Following the planned paths, hidden fault information such as the current in the UHV dense transmission channel is collected. A message feedback mechanism is established in the BeiDou terminal to monitor the message transmission status. In case of packet loss, messages are retransmitted, and a cache stores failed messages, which wait for idle processes to retransmit the messages from the cache area. Using BeiDou satellites, the collected fault information is transmitted with high quality to the master station. At the master server, empirical mode decomposition is applied to the fault information (current data) for a period before and after the fault occurrence. Then, the Hilbert transform is performed on the obtained high-frequency intrinsic mode functions to derive the corresponding time-frequency spectrum. The time of the frequency mutation observed in the time-frequency diagram corresponds to the arrival time of the traveling wave head. Based on this, the fault distance in the UHV dense transmission channel is determined, enabling fault localization. Experimental results demonstrate that the proposed technique offers significant advantages in collecting hidden fault information. It ensures that the success rate of retrieving hidden fault information via BeiDou satellites exceeds 99.5% and enables accurate fault location under different fault conditions.</p>