A composite ultrafiltration membrane containning polyethylene terephthalate (PET) non-woven fabric substrate and poly(vinylidene fluoride)(PVDF) nanofibers as support layer, polyvinyl alcohol(PVA) nanofiber membrane for barrier layer was prepared using electrospinning method. A mixture of acetone and water solution was used for crosslinking treatment to form the dense barrier layer. The ultrafiltration membranes were characterized by Fourier transform infrared(FTIR) spectroscopy, scanning electron micrograph(SEM) and water contact angle(WCA). Filtration performance of the resulting PVA/PVDF composite ultrafiltration membranes was evaluated by the oil/water emulsions separation system. The results showed that the optimal composite ultrafiltration membrane possessed general flux [(42.50 +/- 4.78) L/(m(2) . h)] and high rejection rate [(95.72 +/- 0.33)%] at very low feeding pressure(0.02 MPa), after 5 times recycled, it still has good filter performance. The pure water flux using the dead. end filtrationof composite ultrafiltration membrane at atmospheric pressure was [(3469 +/- 28) L/(m(2) . h)].