Abstract:The underwater acoustic vector sensor is a new kind of underwater sound receiving transducer compared to traditional hydrophones, with the capability to obtain the complete ocean sound field information, including both sound pressure and particle velocity. In particular, the frequencyindependent natural cosine directivity and the advantages of suppressing isotropic marine environmental noise make AVS have great potential applied in underwater security defense, marine resource exploration, long-distance communication and environmental monitoring. This paper reviews the main developments of AVS over the past decade, including the exploration of novel sensing mechanisms, the application of new piezoelectric active materials and the design of innovative structures. Furthermore, the comprehensive challenges to be addressed in future work, such as device design at very low frequencies or in deep ocean conditions, platform suitability considerations, and advanced calibration techniques are analyzed and discussed.