With the large-scale deployment of the low-altitude economy

low-altitude services impose higher requirements on three-dimensional coverage

continuous sensing

and safety supervision in low-altitude airspace. Due to the high mobility of low-altitude flying targets

service data transmission and target sensing need to be jointly guaranteed

which creates an urgent demand for the integrated provision of communication and sensing. In this context

Integrated Sensing and Communication (ISAC) can collaboratively provide both communication and sensing capabilities over a unified network infrastructure

thereby offering critical support for the construction of the low-altitude digital infrastructure. This paper first reviews the domestic and international standardization and research progress

and then summarizes two technical approaches: ISAC base-station-based systems and ISAC UAV-swarm platforms. It further identifies major challenges

including resource competition

insufficient low-altitude three-dimensional coverage

limited sensing accuracy

insufficient sensing trustworthiness

and complex global interference coupling.Finally

a technical roadmap for ISAC networks oriented toward the low-altitude economy is proposed

covering trustworthy echo acquisition

networked cooperative detection and continuous trajectory tracking

AI-based recognition and fusion

multi-source fusion sensing and conflict arbitration

as well as network-level resource and architectural evolution.