The softening system selects the raw water of the boiler house as urban tap water, and its hardness does not meet the boiler feed water requirements, and needs to be softened. The cation exchange softening method has stable treatment effect, and the equipment and operation management are relatively simple. The low-flow flow regenerative sodium ion exchange system has the advantages of good effluent quality, low regeneration liquid consumption, and better regeneration effect than downstream regeneration. Therefore, the design of water treatment determines the use of "low flow rate countercurrent regeneration" sodium ion exchange system. . The resin is used as an exchanger, and the reducing agent is salt. Two sodium ion exchangers were used for rotation operation.