The requirements of drinking water industry for water quality usually need to use pretreated purified water or purified water, TDS is usually below 15mg / L. On the basis of meeting the user's water use standard, Hongjie water science and technology has set liquid level control system in the water tank, pressure protection device in the water pump, on-line water quality detection and control instrument, and PLC programmable controller in the electrical system, so that no one is on duty. At the same time, the unified method of recommendation and customer requirements is adopted in the process material selection, Compared with other similar products, the equipment has higher cost performance and equipment reliability.