The supercritical carbon dioxide (S-CO2) power generation system uses S-CO2 as the working medium and is based on a closed-loop Brayton cycle using real gas. It converts heat released from a heat source into electrical energy through direct or indirect means, and has the advantages of high power density and high cycle efficiency, enabling it to better meet the needs of future naval power development. This article introduces the technical characteristics of the S-CO2 power generation system and summarizes its development history over the past 60 years. For the overall design and power system applications of naval vessels, seven key system design technologies are proposed, covering aspects such as overall design, coordination and matching, operation control, electromagnetic compatibility, vibration and noise reduction, working medium control, safety, and reliability. Based on the methodology of systems engineering, design ideas supporting the design of the S-CO2 power generation system for ships are reviewed.