High voltage disconnecting switch is an important electrical device in the power system. People do not pay attention to daily management and maintenance of the dis-connecting switch because the disconnecting switch structure is relatively simple and its defect is easy to handle. However, in recent years, the failure rate of the pillar insulator of discon-necting switch is on the rise. The failure preventive measures are discussed in detail.% 高压隔离开关是电力系统中重要的开关电气设备，由于隔离开关结构相对简单、缺陷易于处理，因此隔离开关的日常管理和维护不太受人重视。但是近年来，隔离开关的支柱绝缘子发生的故障率呈上升趋势。重点探讨了隔离开关支柱绝缘子故障的预防措施。
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