To solve the problem that the periodic water production of high-flowrate mix bed is usually low due to the non-uniformity of water distribution

numerical simulations are conducted to investigate the water distribution effect by CFD method. Parameters about the porous media model for the resin particles are put forward. The velocity uniformity index of water distribution is identified as a criteria to evaluate the performance of mix beds. Against the disadvantages of the commonly used "water distribution structure with perforated plate and water caps"

the "enhanced two-state water distribution device" and "two-layer perforated plate water distribution device" are proposed

and are optimized constantly based on CFD method. The velocity uniformity index of water distribution is increased continuously

along with the periodic water production

of which the maximum value reaches 1.25 times of the design value.