Offshore pile foundation fixed oil platforms are the main structural form of offshore oil production in China. At present， the tension type external current cathodic protection technology has become the main technical means of cathodic protection for offshore pile foundation fixed jacket platforms. The newly built jacket platform adopts the method of installing a tensioned composite cable electrode system on land， but facing the design height of 338 meters of jacket， it is a huge challenge to install a composite cable about 340 meters long and weighing about 3.5 tons during its horizontal construction process， and there are no relevant research results or industry experience to draw on. In order to solve this problem， this article proposes a static sliding cable composite cable installation method for installation testing. Based on mechanical calculations and 3D simulation， video monitoring， and dynamic monitoring of the actual process of the composite cable， the actual monitoring data is comprehensively compared with theoretical calculation data and onsite test data. The focus is on studying the stress state of the steel wire rope sliding cable and traction steel wire rope during the installation process of the composite cable， the local deflection and overall deflection of the composite cable， and the change law of the composite cable motion posture during the installation process， to verify the feasibility of the impressed current cathodic protection （ICCP） composite cable sliding cable installation scheme for deepwater horizontal jackets.