Abstract: Passive Acoustic Monitoring (PAM) is a technology that can be used to detect, locate, track, and identify targets in the water based on their vocalizations, and it is increasingly being used in fisheries. PAM enables non-invasive monitoring of the distribution, behavior, and population dynamics of fish and marine mammals by recording the sounds produced by aquatic organisms. The main advantages of this technology include its ability to collect data continuously over long periods, regardless of weather conditions, and to obtain critical ecological information without disturbing the target species. In recent years, with advances in acoustic sensors and data processing technologies, PAM has shown great potential in fishery resource assessment, species conservation, and detection of illegal fishing. This paper introduces the key technologies of passive acoustic monitoring, including sensors and devices, data acquisition and processing, and algorithms and analytical methods. It also analyzes the main applications of passive acoustic monitoring in fisheries. Looking ahead, PAM is expected to enable more accurate management and protection of fishery resources through integration with artificial intelligence, machine learning, and big data analytics. However, PAM still faces challenges in practical applications, such as high equipment costs, complex data processing, and interference from the acoustic environment. Therefore, future research should focus on improving the cost-effectiveness and practicality of the technology to support sustainable fisheries management.