Abstract: In the field of fault indicator system in power system, specifically, a plurality of fault indicators distributed on the high-voltage line of the same bus and a zero-voltage start-up unit of the bus, and data mutual transmission and self-registration connection are completed among multiple devices through 5G communication technology; A zero-voltage start-up unit is installed on the bus to collect the conventional zero-voltage signal, detect the zero-voltage transient mutation in real time, and notify all outgoing barrier indicator devices to generate data according to the mutation time to realize distributed management. The zero-voltage start-up unit summarizes the failure time data of the barrier indicator and synthesizes zero sequence. Through zero-sequence voltage and zero-sequence current, analyze and judge the transient fault of the line. Zero-voltage start-up unit, according to the position of each fault indicator, maps it into a topological structure diagram, realizes distributed management, summarizes the data of each topological point, and carries out real-time detection and fault judgment on each line through data summarization, big data storage and big data analysis. Upload the fault point to the master station to complete the grounding fault location in the distribution network.