Underwater laser ranging technology is a crucial approach for ocean exploration and underwater sensing, with broad applications in marine engineering, environmental monitoring, and resource development. Owing to its advantages of rapid and accurate measurement, this technology demonstrates highly efficient detection capabilities in complex aquatic environments, providing strong support for acquiring high-resolution underwater information. This study first introduces the principles and recent technological advancements of four commonly used underwater laser ranging methods, including time-of-flight, phase detection, triangulation, and photon counting. It then reviews the typical application progress of this technology, followed by a comparative analysis of the advantages and limitations of each method in underwater detection. Finally, future development trends and potential applications of underwater laser ranging are discussed.