Water treatment membrane technology plays a vital role in wastewater reuse projects. By using microfiltration (MF), ultrafiltration (UF), nanofiltration (NF) and reverse osmosis (RO) membranes, suspended solids, colloids, organics and dissolved salts in wastewater can be effectively removed, and water recycling can be realised. Microfiltration membranes are mainly used in sewage and wastewater treatment; ultrafiltration membranes are widely used in sewage, wastewater treatment and reuse and feed water purification; nanofiltration membranes are mainly used in purified water, softened water, non-ionised water and seawater desalination; and reverse osmosis (RO) membranes can be used in seawater desalination and other fields. These technologies not only reduce wastewater discharge, but also improve the efficiency of water resources, which is of great significance for environmental protection and sustainable development.