The invention relates to an application method for an intelligent dual-line type expansion and disassembly device for electric power maintenance. The intelligent dual-line type expansion and disassembly device for electric power maintenance comprises a handheld shell, an expansion device, an observation sleeve and a detachable handle. The application method for the intelligent double-line type expansion and disassembly device for electric power maintenance comprises the following steps that 1, the periphery is cleaned; 2, expansion side plates are rotated; 3, the expansion side plates move; 4,the observation sleeve pipe is adjusted; and 5, a bolt or a screw is disassembled. The application method for the intelligent dual-line type expansion and disassembly device for electric power maintenance has the advantages that operation is convenient, the expansion and disassembly device can be held by one hand, and accurate adjustment can be carried out through a thumb; obstacles around the part to be disassembled, such as electric wires or other rubbish can be cleaned, so that the block of the field of view is avoided; and the bolt or the screw needing to be disassembled and assembled isobserved through the observation sleeve, and then the bolt or the screw is disassembled by the detachable handle.