Abstract:Biomimetic undulating propulsion has garnered significant attention for its advantages in high maneuverability, low noise, and enhanced stealth, making it a promising alternative to traditional propeller-based systems for underwater unmanned vehicles. This paper provides a comprehensive review of the current research status in biomimetic undulating propulsion, covering the design and implementation of undulating fin robots, theoretical and numerical studies on propulsion mechanisms, control strategies, and potential applications. Although considerable progress has been made in both motor-driven and smart material-based actuation, the hydrodynamic performance of current prototypes still falls short of biological counterparts. Key challenges remain in multi-modal motion generation, fluid-structure interaction mechanisms, high-fidelity numerical modeling, and robust control strategies. Future research should integrate multidisciplinary approaches to address fundamental issues such as unclear propulsion mechanisms and inadequate performance prediction models, thereby facilitating the practical deployment of undulating propulsion technology.