The invention discloses a long-distance GIL arc discharge fault locating method and a long-distance GIL arc discharge fault locating device. The method comprises the following steps: receiving a soundwave signal and converting the sound wave signal into a sound wave digital electric signal; according to the sound wave digital signal, calculating short-time energy of each microphone flag frame, determining M microphone positions closest to a sound source; determining time difference between any two of the M microphones, and determining a fault point position according to distance between the sound source and the microphone. The method and the device provided by the invention solve problems of high consumption of labor force, poor locating accuracy and failure of usage in long-term online monitoring of an artificial process, overcome defects of an ultrasonic method and an ultrahigh frequency method, such as high need of microphones, complex system composition, high workload of mountingand maintenance, liable to be affected by electromagnetic interference, relatively poor locating reliability and relatively high equipment cost, and realize fast locating for fault points through monitoring and analyzing an audible sound signal generated by GIL internal arc discharge.