Abstract: The construction scheme of offshore intermediate joint in a domestic high voltage cable project was introduced.The plan maked requirements for meteorological environment and ship positioning of offshore construction.A work shed was added to maintain the ambient temperature and humidity during electrical connection construction.The optical and electrical properties of the intermediate joint before and after the manufacturing process were tested to ensure the effective implementation of the scheme and the safety and reliability of the completed joint.In the electrical connection part, solutions were given for the insulation surface treatment, insulation retraction, interface pressure and other problems, in which the electrical connection joint uses the “品”shape scheme layout.Under the premise of ensuring quality and safety, the scheme choosed synchronous construction of optical fiber connection and joint mechanical protection shell installation.Finally, the precautions and post-protection points of joint sinking construction were introduced.