Abstract: This paper discusses the control measures for potential tramsformer（PT） secondary reverse charging caused by poor contact of isolator auxiliary contacts, analyzes the causes of potential transformer secondary reverse charging, and proposes control measures including the monitoring of background remote control logic blocking, circuit bus bar switching circuit blocking, and strengthened measures of monitoring and warning for switching device bus bar switch contacts, technically reducing the risk of PT secondary reverse charging caused by incorrect operation of switcher auxiliary contacts, which plays a positive role for preventing PT secondary reverse charging.