Water source pollution is becoming more and more serious. Polluted rivers, lakes and groundwater are the most common sources of industrial and domestic water. Due to pollution, there are a lot of harmful and toxic pollutants in water bodies. It is reported that there are 2221 kinds of known organic substances in water, some of which are carcinogens. Therefore, it is the safest measure to further purify tap water to meet the requirements of pure water. In China, the water purifier should meet the relevant requirements of the National Provisions on the Health Safety and Function Evaluation of Reverse Osmosis Drinking Water Treatment Devices (2001).