Abstract: In order to conduct a more comprehensive carbon footprint study of Liquefied Natural Gas（LNG）-powered ship types,H-LCA is proposed to analyze the carbon emissions of one-thousand-tank LNG-powered ships during the construction and operation phases.The sensitivity analysis of three factors affecting carbon emission,namely methane leakage rate,ship carrying capacity,and main engine type,shows that methane leakage rate and main engine type are the key factors affecting the carbon reduction potential of LNG-powered ships,and that when the leakage rate exceeds 2.5%,the LNG-powered ship does not have the advantage of carbon reduction,so it can be equipped with a high-efficiency main engine to minimize methane leakage and reduce carbon emission;the carrying capacity of the ship is an important factor affecting the carbon reduction potential of LNG-powered ships,and the ship can be equipped with a high-efficiency main engine to minimize methane leakage.The ship’s carrying capacity is an important factor affecting the carbon reduction potential of LNGpowered ships.The higher the carrying capacity,the better the carbon emission level of LNG-powered ships under the system functional unit,and in the future,LNG-powered ships can also improve the carbon reduction benefit by improving the carrying capacity.