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Abstract: With the rapid development of the low-altitude economy, low-altitude unmanned aerial vehicle (UAV) swarms are emerging as important components of sixth-generation (6G) mobile communication networks, facilitating “full coverage” and “Internet of Intelligence.” integrated sensing and communication (ISAC) deeply integrates sensing functionality into wireless communication networks by sharing wireless infrastructures and resources such as base stations, antennas, radio frequency chains, and signal waveforms, thereby significantly improving the performance of low-altitude UAV swarms. This paper reviews the research status of low-altitude UAV swarm ISAC systems, analyzes the new challenges arising from key features of UAV swarms, including low–slow–small characteristics, high density, large quantity, complex low-altitude environments, and high swarm coordination requirements, presents a vision for future deployment, and proposes the so-called “Ten Ones” performance metrics tailored to low-altitude UAV swarm ISAC. To realize these ambitious key performance indicators for future UAV swarm ISAC, several promising technologies are discussed, such as new array architectures, including extremely-large multiple-input multiple-output (XL-MIMO), sparse XL-MIMO, and reconfigurable antenna arrays, sparse time–;frequency resource allocation, and channel knowledge maps. Furthermore, the potential of exploiting UAV swarms as airborne ISAC platforms is discussed. Finally, future research directions are outlined, offering a guideline for the design and development of low-altitude UAV swarm ISAC systems.

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