The invention relates to the electrical technical field. An automatic underground power line fault positioning and
warning system comprises at least three sensors for detecting the working state of an underground power line, wherein each sensor is a
wireless passive sensor and is provided with a communication module, each communication module is provided with at least two different kinds of communication media and comprises an
ultrasonic communication module with an ultrasonic
signal as the communication medium and a radiocommunication module with a
radio signal as the communication medium, each sensor is connected with a main unit
server through the corresponding communication module, and
feature data for
identity recognition are arranged in each sensor. Due to the fact that each communication module is provided with different communication media for joint communication, the
system is suitable for communication conditions in different environments and with different distances,
signal transmission stability is improved, and normal
signal transmission can still be guaranteed when any communication module breaks down. Furthermore,
feature data for
identity recognition are transmitted outside through the communication modules, so that positioning is facilitated.