The phase¢òproject of seawater desalination in Yongxin not only supplies the necessary industrial water for the power plant, but also delivers the high quality water for the subsequent boiler make up water system; compared with the pretreated surface water by tradilitional technology, the fresh water extracted from seawater by reverse osmosis technology can optimize the operating conditions in the followed system, which can extend the service lifetime of the equipment. And it will be untroubled when the river is dried up during dry season.