<p>Ultrasound, as an emerging non-thermal food processing technology, has been widely applied in the field of aquatic product processing. Ultrasound generates a cavitation effect, which induces mechanical and thermal effects. These effects influence the quality attributes and related process variables of aquatic products, thereby maintaining their nutritional and sensory characteristics. This paper reviews the principles of ultrasound for preserving the quality of aquatic products, its various application methods, and its impact on the efficiency and quality of key aquatic product processes (including thawing, freezing, pickling, and pretreatment). It also discusses the challenges encountered and prospects in this field. The results show that ultrasound-assisted processing effectively shortens the thawing and freezing time of aquatic products, while improving their physicochemical quality attributes such as texture, microstructure, and microbial quality. Therefore, ultrasound has great potential in the quality protection of aquatic products. It provides an innovative quality protection solution for the aquatic industry and promotes the progress of this field.</p>