Abstract: This paper reviews the historical development, research progress, and major challenges of nuclear-powered civilian vessels, and further explores their developmental trends and potential application pathways. First, it outlines the historical evolution of three typical applications, namely nuclear-powered merchant ships, nuclear-powered icebreakers, and offshore floating nuclear power plants, and summarizes the current status of relevant standards, regulations, and regulatory frameworks. Secondly, this study systematically reviews the current international research progress on various technical routes such as pressurized water reactors, fast reactors, molten salt reactors, small modular reactors, and micro modular reactors, and analyzes their potential advantages in civilian ship applications, as well as their limitations in terms of safety, economy, and regulation. Finally, the paper forecasts trends towards miniaturization, modularization, and inherent safety, and suggests steady progress through land-based testing, demonstration operations on fixed routes, segmented push-tug shipping modes, focused application scenarios, with the goal of improving economic efficiency and regulatory framework refinement.