High-entropy alloys (HEAs), also called multi-principal-elements alloys, possess extraordinary mechanical properties, including high strength and hardness, thermal stability, corrosion resistance and radiation resistance, due to their unique and complex microstructures. The comprehensive understanding of their microstructures down to atomic level plays a vital role in developing HEAs, for tuning manufacturing parameters, examining their phase stabilities under severe conditions for future applications, and determining origins of their excellent mechanical properties. The expansion of the fundamental knowledge of the microstructure strongly relies on the advance of high-resolution analytical techniques. As a state-of-the-art technique, atom probe tomography (APT), with a high spatial resolution and ability in detecting individual atoms, has emerged as an important tool in studying HEAs. Herein, an effort is made to review the recent application of APT in understanding HEAs. It begins with the experimental approaches in using APT to reveal atomic-scale structural and chemical information of HEAs, and follows by typical applications of APT in high-performance HEAs processed by different routes, understanding their microstructural stability, and structure–property relationships. Finally, major challenges and perspectives in APT applications to address fundamental science of HEAs are discussed.

高熵合金 (HEA)，也称为多主元素合金，由于其独特而复杂的微观结构，具有非凡的机械性能，包括高强度和硬度、热稳定性、耐腐蚀性和耐辐射性。对其微观结构的全面了解直至原子水平，对于开发 HEA、调整制造参数、检查其在未来应用的严苛条件下的相稳定性以及确定其优异机械性能的来源，都起着至关重要的作用。微观结构基础知识的扩展在很大程度上依赖于高分辨率分析技术的进步。作为最先进的技术，原子探针断层扫描 (APT)，具有高空间分辨率和检测单个原子的能力，已成为研究 HEA 的重要工具。在此，努力回顾 APT 在理解 HEA 中的最新应用。它从使用 APT 揭示 HEA 的原子级结构和化学信息的实验方法开始，然后是 APT 在不同路线处理的高性能 HEA 中的典型应用，了解它们的微观结构稳定性和结构 - 性能关系。最后，讨论了 APT 应用中解决 HEA 基础科学的主要挑战和前景。接下来是APT在不同路线处理的高性能HEA中的典型应用，了解它们的微观结构稳定性和结构-性能关系。最后，讨论了 APT 应用中解决 HEA 基础科学的主要挑战和前景。接下来是APT在不同路线处理的高性能HEA中的典型应用，了解它们的微观结构稳定性和结构-性能关系。最后，讨论了 APT 应用中解决 HEA 基础科学的主要挑战和前景。