The ultra pure water equipment used in the solar photovoltaic industry adopts EDI technology, which uses voltage to selectively migrate the electric ions in the water. Through the adsorption effect of ion exchange resin, the electric ions in the water are directed towards the anion filtration membrane and cation filtration membrane, and finally form concentrated water for discharge. The entire preparation process uses physical technology, without the need for any chemical agents. The water production process is continuous, with low pollution emissions, making it a very environmentally friendly ultra pure water preparation technology.