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In this paper, a hollow fiber composite nanofiltration membrane was developed by electron beam radiation crosslinking, using polysulfone （PSF） ultrafiltation membrane as support membrane, poly[2-（N,N-dimethyl amino）ethyl methacrylate] （PDMAEMA） as coating material. Using 0.017mol/L MgSO4 solution as the feed liquid, under an operating pressure of 0.7MPa, 27℃, the inside-flow hollow fiber nanofiltration membrane has a salt rejection above 84.8%, and a permeating flux of 5.6L/（m2.h）.The concentration of PDM, the pH value of PDM solution, the drying time, the content of additional NaHC03 and the initiator of AIBN was investigated, the above factors affect the separation characteristics. The pH value of PDM solution directly affected the rejection of composite nanofiltration membrane, when the pH of PDM solution is somewhat above 7, it is beneficial for PDMAEMA crosslinking, the best pH of PDMAEMA solution is 10.2; the NaHCO3 added into the interfacial polymerization system influence on the characteristics of the NF membrane, it can just the pH of the PDMAEMA solution and maintain the macromolecule conformation of the PDMAEMA, the PDMAEMA aqueous solution with the NaHCO3 of 0.08%（wt%）, the NF membrane performance the best rejection and flux.PDMAEMA composite NF membrane has the rejection and selectivity towards heavy metal salt, so the membrane can be used for recycle and concentration of the waste water which containing heavy metal ions. Meanwhile, PDMAEMA composite NF membrane could reject the small neutral organics, achieving the separation between monosaccharide and polysaccharide. The PDMAEMA NF membrane has high rejection on phenol, for its benzene ring, its rejection is about 90%. Also, changing the operating conditions, temperature, pressure, pH, concentrations of feed liquid and so on, the priorities of NF membrane have been tested farther.Finally, the PDMAEMA composite NF membrane, the NF90 and NF270 membranes were applied to the rejection of ionic liquids. The results show that NF90 membrane can effectively prevent the ionic liquids through the membrane.
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