As an important research tool of quantum technology, acoustic quantum states in the optomechanical system play an important role in quantum communication, quantum computing, precision measurement, and other fields. This paper reviews the development of acoustic quantum states in the optomechanical system, including the basic physical process of the optoacoustic interaction, the generation and regulation of acoustic quantum states in the optomechanical system, and focuses on the research progress of acoustic quantum states in the application direction of microwave-optical conversion, on-chip information processing, precision measurement, and hybrid systems, as well as the advantages and challenges associated with each direction. Finally, the future development direction of acoustic quantum states in optomechanical crystals is discussed, including discovering more optomechanical coupling mechanisms, increasing the intensity of optomechanical coupling, breaking the quantum limit, large-scale integrated device preparation, and expanding more applications with more other systems.