Ultrafiltration is a membrane separation technology that can purify and separate solutions.The ultrafiltration membrane system is a solution separation device with ultrafiltration membrane silk as the filter medium and the pressure difference on both sides of the membrane as the driving force. It only allows the solvent (such as water molecules),inorganic salts and small molecular organic substances in the solution to pass through, while retaining the macromolecular substances such as suspended solids, colloids, proteins and microorganisms in the solution, so as to achieve the purpose of purification or separation.