A high-velocity double-chamber bed (HDCB) is anew type demineralizer whose flow velocity can exceed 40 m/h. This paper analyses the six factors that influence operational resistance and points out that the theoretical flow velocity of the HDCB can surpass 40 m/h by increasing the diameter of resins and applying inert plastic balls, etc. The operational results of projects showed that the flow velocity of the HDCB reached 40 m/h and the benefit was remarkable. Results indicate that a HDCB is superior to a double-chamber fluidised bed (DCF) in some respects such as the use of simple equipment, convenient operation, lower water consumption and a lower resin make-up ratio, etc., and a HDCB is also superior to a RO system in other areas such as a lower requirement for pre-treatment, simple flow, easy maintainence, easy adjustment, and water conservation. A case study in a chemical plant showed that the investment cost of HDCBs is 60.7% lower than RO, and the operation cost of HDCBs is 31.6% lower than RO and 15.0% lower than DCFs; water consumption is 21% lower than RO and 12.5% lower than DCFs. Thus, HDCBs are suitable for water-scarce regions.