Ultra filtration technic is abroad used in the field of water filtration, solution separated, concentration, recover useful materials from wastewater and recycle of waste water purification. Its feature is easy process, no require with heating, saving energy, running under low-pressure and small space occupied. Ultra filtration is a membrane separated process of screening with separation Ultra filtration can remove the particles, colloid, bacteria bedding and macromolecule organic substances. It used abroad in the substances separated, concentration, purification. Ultra filtration process haven’t the mutually transformation and operation in normal temperature. It particularly adapt to thermal sensitivity substance separate. It has good performance on high temperature resistance, acid and alkali resistance, oxidation resistance. It could continuous service below 600C and at pH value of 2-11 in a long period. Hollow-fiber ultra filtration membrane is one of the most advanced ultra filtration technics. The external diameter of hollow-fiber is 0.5-2.0mm and internal diameter is 0.3-1.4mm. There are micropore bestrew on the wall of the hollow-fiber. Aperture express by molecular weight of the trapped substances which can from thousands to hundred thousands. Raw water flows at the outside.