Abstract: Nanofiltration membranes are playing more and more important roles in the fields of sea water desalination and drinking water purification. The ion track membrane (ITM), as a kind of important separation membrane with uniform pore size, regulable pore density, and free-defect surface, has potential permission in water treatments and precise separation. The thin ITMs with high pore density as substrates have great potential in the preparation of high-performance nanofiltration membranes. Herein, we report a triple-layered organic-inorganic composite membrane with zirconia (ZrO₂) as a selective layer and polyethylene terephthalate ion track membrane (PET ITM) as support. The polydopamine (PDA)-polyethyleneimine (PEI) intermediate coating facilitates inorganic nanoparticles to form an inorganic layer on the membrane surfaces. The composite membrane can achieve partial rejection for various kinds of salts and exhibit a salt retention order of Na₂SO₄>MgSO₄>MgCl₂>NaCl.