Floating bed is a single-chamber floating bed equipped with a porous plate with two water caps, divided into two chambers. The upper chamber is filled with strong resin, and the lower chamber is filled with weak resin. In the two-compartment interactive bed, the two resins provide favorable working conditions for each other, that is, weak resins provide high regeneration level for strong resins, thus improving the working exchange capacity of strong trees, while strong resins allow weak resins to have higher leakage, giving full play to the strengths of weak resins. The combination of weak resins with high regeneration efficiency, high regeneration capacity and strong resins working at high regeneration level can make the average working exchange capacity of cation exchange process reach 1300-1700 mep/LR under the regeneration ratio of 1.O-1.3. The average working exchange capacity of anion exchange process reaches 600-1700 mep/LR. 900mep / LR- is beyond the reach of other technologies. In addition, the double-chamber floating bed has the characteristics of low water consumption, simple operation and high flow rate.