Abstract: In order to implement the "double-carbon" (namely, carbon emissions peak and carbon neutrality) goal, China will vigorously build a new power system with new energy as the main body. Due to the reverse distribution of consumption and supply of new energy in China, UHVDC transmission technology will still be the most economical way of energy consumption across regions in the future power system. In order to solve the problems that the traditional converter technology depends on the voltage strength of AC system, poor independence and adaptability, and high resonance risk, this paper proposes the UHVDC SLCC converter technology, and carries out a feasibility study from aspects of the topology, working principle, model building, transient and steady-state characteristics, technical and economic analysis. The research shows that this technology can improve the inherent defects of traditional DC transmission technology to a certain extent, and provide necessary support and guarantee for the safe and stable operation of DC transmission system under the development of new power system in the future.