SW series reverse osmosis membrane element is used for high brine polyamide composite membrane, with low pressure operation, high water production, good salt removal performance. Due to the use of special processes to treat the membrane surface, increase the hydrophilicity of the membrane surface, thereby reducing the deposition of pollutants and salts on the membrane surface, to achieve the effect of anti-pollution, suitable for desalination treatment of industrial wastewater, high salt water, water and other water sources with salt content less than 20000ppm, of which 8-inch membrane is mainly used in large and medium-sized industrial water reuse, containing a small amount of water Machine pollutants or high salt industrial wastewater, urban sewage and other water sources treatment. The 4-inch membrane is especially suitable for small-scale industrial water reuse, industrial wastewater containing a small amount of organic pollutants or high salt, urban sewage and other water sources.