Abstract: Air-coupled ultrasonic technology is a non-destructive testing technology that uses air as the coupling medium to achieve non-contact excitation, propagation, and signal acquisition of ultrasonic waves between the transducer, air, and the tested material, thereby enabling material evaluation. This technology does not require the use of liquid coupling agents, which can effectively reduce the risk of coupling agents contaminating or damaging sensitive materials in traditional ultrasonic testing. Therefore, it is conducive to integration with automated detection platforms and enables online detection of the internal quality of materials. Based on an exposition of the working principle and typical testing methods of air-coupled ultrasonic technology, this paper systematically reviews the core hardware and software systems of the technology, summarizes its typical applications in high-end manufacturing industries such as aerospace, new energy storage, and rail transit, and further analyzes its in-depth integration with artificial intelligence, robotics, and 5G communication technologies as well as its future development trends, demonstrating that this technology holds broad prospects for industrial applications.