The seawater desalination, daily output reaching 2 tones, can be used in islands and coastal water shortage cities. This method can remove the inorganic salt, heavy metal ions, bacteria and germs, the harmful ingredients in the water, and sea water can be desalinated into high quality water conforming to national drinking water standard. This system uses the most advanced fully automatic multichannel combination valve to realize automatic flow back flush and washing process. The shell and pipeline are made out of corrosion-resistant material, ensure the durability of the whole system. The Host RO system is used the most advanced RO system software and the high quality membrane element. The system is designed on the base of productivity, combined the unique energy recycle technology, to ensure low energy consumption. Besides, it equips advanced Inspection and monitoring system, which makes the system work stably and produces high quality water and provide accurate info for running conditions. The control instruments and pressure relief and discharge piping keep the system safe, stable and simple maintain.