With increasing quantities of fishing boats, the nitrogen oxides emission from by diesel engines is polluting the atmosphere accounting for 5% to 10% of air pollution. Replacing diesel with LNG can decrease carbon emissions by 10% to 20%, nitrogen oxide emissions by 90% and sulfide&particle emissions by 100%. What is more, cold energy from LNG evaporation can be recovered for fish freezing and cold storage; heat energy from burned LNG can be recovered for fish drying and water heating.