在全国统一电力市场建设和高比例可再生能源并网的背景下，我国正形成多层级跨区域市场格局。不同层级、区域和时间点达成的交易在实时交割中共同作用于同一互联电网，使高效、准确地计算可用输电能力及设计其分配机制成为关键问题。首先梳理了可用输电能力的概念与理论框架，并总结了现有计算方法的主要技术路线及其不足。随后汇总典型市场中同时涉及可用输电能力的计算与分配机制的研究进展，并分析其特点与局限。在此基础上，系统比较美国PJM、欧洲以及我国国家电网和南方电网的可用输电能力计算与分配机制，揭示不同机制背后的制度逻辑与市场适配性。最后，从学术研究与市场实践两个层面总结可用输电能力的计算和分配机制未来的发展方向，并结合我国市场建设需求提出相应的优化建议。

Against the backdrop of building a unified national electricity market and integrating high shares of renewable energy, China is forming a multi-level, cross-regional market structure. Transactions concluded at different levels, regions, and time points ultimately act on the same interconnected grid during real-time delivery, making the efficient and accurate calculation of available transfer capability (ATC) and the design of its allocation mechanisms critical. This paper first clarifies the concept and theoretical framework of ATC, and summarizes the main technical approaches and limitations of existing calculation methods. It then reviews research progress in typical markets that simultaneously address ATC calculation and allocation, highlighting their characteristics and shortcomings. Building on this, the paper compares ATC calculation and allocation mechanisms in PJM, Europe, and the China State Grid and China Southern Grid regions, revealing the institutional logic and market suitability underlying different designs. Finally, it outlines future research and practical development directions and proposes optimization recommendations for ATC calculation and allocation mechanisms in light of China’s market development needs.