Distributed optical fiber acoustic sensing (DAS) technology based on coherent Rayleigh scattering can obtain the vibration and sound field information along the optical fiber in real time. Recently, DAS has received extensive attention from scholars in many fields, due to its unique advantages such as large sensing range and high time-and-space resolution. In this paper, the fundamental sensing mechanism of DAS is introduced. The research progress on key scientific and technological issues, such as coherent fading suppression, response bandwidth enhancement, and spatial resolution optimization, is briefly reviewed. The application progress of DAS in perimeter security, rail transportation, and other fields is also described. Finally, the potential future research directions are discussed and speculated.