Abstract: An abnormal heating event of rheological joint in 500 kV substation is analyzed. Through operation and maintenance control, robot temperature measurement, maintenance plan management and other means, the abnormal heating of rheological joints is tracked and monitored. Finally, the failure is dealt with by making rational use of the outage plan. Through this abnormal event, four improvement measures are proposed, which scientifically and reasonably improve the ability of defect handling and maintenance strategy of substation equipment.