Post-installation method of cable protection pipe

The invention discloses a post-installation method for a cable protection pipe. The post-installation method comprises the following steps that S1, an operation platform is erected at a jacket leg and a cabled aisle near the post-installation position of the cable protection pipe; s2, a plurality of lifting lugs are welded to the jacket legs above the operation platform and the lower portion of the bottom deck of the block correspondingly, and each lifting lug is provided with a clamping ring and a hoisting machine; s3, the cable protection pipes prefabricated in a segmented mode are conveyed to an operation platform, and then the segmented cable protection pipes are welded and assembled; s4, a hoisting machine is adopted to lift the horizontally-placed cable protection pipe from the operation platform, and then the operation platform is dismantled; s5, a clamp installed on the jacket leg in advance is opened, the hoisting machine is adjusted to enable the cable protection pipe to be parallel to the jacket le