(EDI, company - deionization) ，Electro-deionization is a kind of using mixed ion of Yin and Yang of the water adsorption and ion exchange resin, at the same time, the adsorption of ions and under the action of dc voltage, respectively through ion exchange membrane into the thick of Yin and Yang very water chamber and removed, on the other hand, under the action of dc voltage, water can produce enough dissociation of H + ions and OH - ions, in order to realize the continuous deep desalting. This new technology can replace the traditional ion exchange (DI), produce the resistance rate is as high as 18 m Ω pure water. EDI's most significant advantage is that it no longer requires the regeneration of ion exchange resins with acids and bases, making it more environmentally friendly.