Traditional polymer membranes prepared by phase inversion process have the problems of low flux and serious fouling when they were used for oil/water separation. In this work, an alkaline-induced phase inversion process is developed for the superhydrophilic/underwater superoleophobic polyacrylonitrile (PAN) ultrafiltration membrane. The as-prepared PAN ultrafiltration membrane could effectively separate oil-in-H2O emulsions with a high flux up to 2270 L/m(2) h bar and an extremely high rejection while the oil residual in filtrate after one-time separation is lower than 10 ppm. Also, the PAN membrane showed ultralow oil adhesion and antifouling properties and can be easily recycled with flux recovery ratio of 85%. This new PAN membrane has a great potential for treating oily wastewater. (C) 2016 Elsevier B.V. All rights reserved.