The small QHML microporous membrane filter has the advantages of high filtration accuracy, fast filtration speed, low adsorption, no medium shedding, no leakage, acid and alkali corrosion resistance, and easy operation. It can remove bacteria and particles in injection water and liquid medicine. It can be backwashed during cleaning and can be used to form second, third, and fourth level filters according to different user needs to achieve filtration effect. It is widely used in sterilization and clarification of pharmaceuticals, large infusion solutions, pure water, and biotechnology.