Abstract: The main factors affecting the deformation of cable support such as the cable electric power, the form of the support section and the connection mode of the support ends are analyzed based on the deformation data of cable support for a number of cable tunnel projects that have been put into production contracted by Inner Mongolia Electric Power Survey & Design Institute Co., Ltd. in the paper. Put forward the prevention measures as changing the type of support section, reducing the influence of electric force and improving the mode of the end connection to reduce the deformation rate of cable support.