Abstract In this study, we developed a comprehensive test system for ship-model testing in actual wind, wave, and current flow environments. The resistance and propulsion performance of a 25-m-long ship model were analysed, and corresponding correction methods were developed to determine the performance in actual sea conditions. The effects of an energy-saving device on the ship performance under actual sea conditions were assessed using this platform. The proposed methodology and technique are reliable and promising, and can provide a basis for the development of new ship testing techniques.