The invention relates to the field of 66 kV disconnecting switch interruption maintenance, in particular to a GW5 disconnecting switch unilateral power failure operating method. The method is characterized in that an operator rises to one side of the disconnecting switch unilateral power failure along an insulation herringbone ladder, the safety distance between an equal potential operator and an actual electrified body is no less than 0.7m, the distance between the equal potential operator and an adjacent-phrase electrified body is no less than 0.9m, when the equal potential operator operates on the herringbone rigid ladder or enters a highfield along the herringbone rigid ladder, a combined gap formed by a gap between the equal potential operator and a grounding body and gaps among the equal potential operator and the electrified bodes is no less than 0.8m, and the equal potential operator processes a connecting point and replaces a drainage wire at the top of the insulation herringbone ladder. Compared with the prior art, the GW5 disconnecting switch unilateral power failure operating method has the advantages that the requirements that the operations such as processing of the connecting point and disassembling and assembling of the drainage wire are conducted on the GW5 disconnecting switch unilateral power failure are met, operation is safe, convenient and quick, reliability of power supply by a power grid is improved, and personal safety and reliable operation of electrical equipment are ensured.