Pipeline transportation is an economical and effective way for transferring carbon dioxide (CO2) to the sea, serving as a key procedure for an offshore carbon capture, utilization and sequestration (CCUS) project, as well as a core technology for the large-scale construction of CCUS projects in China. This study clarifies the advantages of China in the construction of offshore CCUS projects, typical offshore carbon pipeline scenarios, and typical offshore CO2 transportation modes. It also reviews the technologies and projects in China and abroad regarding offshore CO2 transportation via pipelines. The current technologies relevant to offshore CO2 pipeline transportation are systematically reviewed. Specifically, the process technologies include CO2 fluid state analysis and flow assurance; corrosion evaluation, monitoring, and early warning; real-time monitoring of pipe leakage; and release of high-pressure CO2 and its environmental impacts. The material technologies include the fracture of pipeline materials and its mitigation, high corrosion-resistant and sealing materials, key corrosion-control techniques for the long-term operation of pipelines, and corrosion risk evaluation of CO2 injection wells. Further efforts should focus on the following aspects: material selection systems for the complex conditions during offshore CO2 pipeline transportation, full-chain intelligent management and digital twin technologies for CO2 pipelines, key technologies regarding the whole life-time operation of subsea CO2 pipelines, and evaluation and assurance techniques for the transferred transportation pipelines. Furthermore, the following suggestions are proposed to promote the high-quality development of the offshore CO2 pipeline transportation system in China: (1) promoting the planning of offshore CO2 pipeline networks, (2) expanding interdisciplinary innovations, (3) establishing standards systems that applicable to both onshore and offshore scenarios, and (4) encouraging the participation of diversified technology service enterprises.