Reverse osmosis (RO) membrane is a kind of artificial semi-permeable membrane with certain characteristics made by simulating bio-semipermeable membrane. It is the core component of RO technology. Reverse osmosis (RO) technology is based on the separation of water from other substances by the action of osmotic pressure higher than the solution. The pore size of reverse osmosis membrane is very small, so it can effectively remove dissolved salts, colloids, microorganisms, organic matter in water. The system has the advantages of good water quality, low energy consumption, no pollution, simple process and easy operation.