Abstract: Addressing the typical defects of disconnector switches in ultra-high and extra-high voltage substations, such as overheating of contacts, broken insulators, and mechanical jamming, which lead to a high equipment failure rate over long-term operation, this paper systematically analyzes reliability influencing factors such as design defects, material aging, and inadequate manufacturing processes. It proposes multi-dimensional technical improvement plans from aspects such as key structural optimization and transmission system reliability enhancement, providing important guidance for improving the operational reliability of disconnector switches..