Abstract: In the long-term operation of substation distribution network switchgear, the performance of internal insulation system will continue to deteriorate, and it is often accompanied by partial discharge, which will lead to power accidents if serious. The traditional monitoring technology of switch cabinet operation state has limitations. For example, over-reliance on manual experience and a single detection method will cause problems such as missed detection. Therefore, from a new research perspective, this paper integrates intelligent technologies such as emerging Internet of Things and intelligent sensors to establish an intelligent monitoring system for the maintenance of switch cabinet without power outage, so as to ensure the safe operation of substation switch cabinet. This intelligent monitoring system can intelligent-ly perceive the operation state of the switch cabinet, intelligently analyze the monitoring data and diagnose the state of the equipment, grasp the operation state in real time, discover the defect problems in time, evaluate the push abnormal information and the maintenance strategy suggestions. Therefore, the system can provide data support for the maintenance personnel to develop the maintenance strategy, so that it can find the fault in time and effectively, and avoid the accident casualties caused by partial discharge.