Abstract: Against the backdrop of global low-carbon electricity and the construction of new power systems, traditional cables struggle to meet demands due to issues such as high losses and limited transmission capacity. High-temperature superconducting technology, with its zero resistance and high current-carrying density, has emerged as a key breakthrough direction. High-temperature superconducting DC cable technology was focused on in this paper, elaborating on its development history and engineering applications, with a focus on analyzing the technical characteristics of Suzhou Tongli high-temperature superconducting DC cable demonstration project. The superconducting DC cable employed in this project was based on independently developed YBCO tapes and adopts a coaxial structure of positive and negative electrodes,with a rated current of 4 500 A and a power transmission of 3.4 MW. Compared with the traditional cable scheme, it has significant advantages in terms of pipeline corridor space occupation (only 67.7% of the traditional scheme), flexibility of power supply mode, long-term expansion capability, and line voltage drop (reduced by 99.9%). Grid-connected operation of the demonstration project could provide engineering experience and data support for practical application of high-temperature superconducting technology in DC power transmission of medium and low-voltage distribution networks, and be of great significance for promoting the construction of new power systems and achieving the dual carbon goals.