The cooling effect of the air cooler used for soft water cooling of small and medium-sized blast furnaces fluctuates with the seasons. In summer, the highest water temperature entering the blast furnace reaches 70C/L, which affects the safety, high yield, and service life of the blast furnace. Plate heat exchangers use corrugated plates as the heat transfer surface, with high heat transfer coefficient, small volume, easy disassembly and cleaning, high heat transfer intensity, and good heat transfer effect. According to the characteristics of large flow rate and small temperature difference in the cooling soft water system of small and medium-sized blast furnaces, it is recommended to choose 316 or 316L stainless steel material, short and bulky structure, two on standby and one on standby, and three parallel plate heat exchangers. Using BR1.1xC (1.0/100) 200.2 water water plate heat exchanger, the temperature of softened water entering the blast furnace remains stable at 34-39 ° C throughout the year