Abstract: Xuanwei, Yunnan Province is located in the Xiaojiang earthquake zone and has rainy and snowy weather in winter. 12 m poles are mostly used in mountainous areas. The 12 m pole has a mass of 1020 kg. The movable pulley block is used for lifting the electric pole. The movable pulley block saves half the effort. When lifting, it bears triangular force. By improving the triangular derrick to the single angle derrick, three main poles can be changed into one main pole. The weight is reduced by 2 / 3. The number of people decreased by 2 / 3. The safety and reliability are greatly improved.