A new sea-water desalination plant is developed according to the problems of large shell volume and high cost of the marine separating-plate type fresh water generator which is nowadays widely used in industry. The heavy copper shell is abandoned through the structural optimization of the heat exchange plate and reasonable design of the flow-path, resulting in the great reduction of the plant volume and production cost, as well as convenient installation and maintenance. The calculation and analysis indicate that the structure of the new plant is reasonable and reliable with the better thermodynamic properties, such as water production ratio, unit heat consumption and unit freshwater energy consumption, than those of the traditional separating-plate type fresh water generator. The mechanical properties of the new seawater desalination plant are simulated and analyzed by using the ANSYS Workbench Platform to further prove its rationality and reliability.