Abstract: The operation state of the collector ring and carbon brush of the generator rotor affects the safe and stable operation of the generator set. When the collector ring and carbon brush have abnormalities and faults, it is necessary to find and deal with them as soon as possible to avoid expanding the accident. At present, the state monitoring of collector ring and carbon brush mainly relies on manual inspection, which is inefficient and cannot be monitored in real time, and there are certain potential safety hazards. This paper studies and establishes a fault monitoring system of generator rotor collecting ring carbon brush. Through the real-time collection and analysis of arc light, temperature and electrical quantity data, the relevant data are displayed and alarmed, so as to improve the monitoring efficiency and level and ensure the safe operation of the generator set.