The ion exchange method is to continuously pass water through a cation exchanger to exchange calcium and magnesium ions that constitute the hardness of water with sodium ions or hydrogen ions in the ion exchanger. The calcium and magnesium ions are replaced by sodium or hydrogen ions to obtain water quality. Softening effect. Common ion exchangers include cation exchange resin and sulfonated coal. The working exchange capacity of the ion exchanger is limited. When it loses its exchange capacity, it must be regenerated. During the operation of ion exchange resin, the total salt content of raw water and its components, the height of the resin layer, the operating flow rate, the water temperature, the regeneration method, the type and purity of the regeneration agent, the concentration and temperature of the regeneration solution, the regeneration flow rate, the amount of regeneration agent, etc. The actual working exchange capacity of the resin. The ion exchange method will produce a certain degree of corrosiveness in water, and it will affect three aspects: one will produce metal corrosion by-products in water, the second will change the chemical properties of water, and the third will damage the surface of the water supply pipe network. Film, thereby corroding the pipe network. Therefore, it is very important to control the corrosion of water.