Reverse osmosis membranes are artificial semi-permeable membranes with certain characteristics made by simulating biological semi-permeable membranes and are the core components of reverse osmosis technology. The principle of reverse osmosis technology is that under the action of a pressure higher than the osmotic pressure of the solution, other substances cannot pass through the semi-permeable membrane, thus separating these substances from water. The pore size of reverse osmosis membranes is extremely small, thus they can effectively remove dissolved salts, colloids, microorganisms, organic matter and other substances from water. The system has the advantages of good water quality, low energy consumption, no pollution, simple process and easy operation.