Polyvinylidene fluoride (PVDF) ultrafiltration membranes with sodium alginate (SA) as the “fouled surface” were prepared, in an effort to control irreversible membrane fouling in mimetic sewage treatment processes. The anchored SA layer improved the wetting ability of the PVDF membrane surface and used as a functional antifouling coating to improve the antifouling ability towards organic pollutants. The modified membrane (S-T-0.3) exhibited excellent fouling resistance, with the irreversible fouling ratio (IFR) values of 9%, 1%, 8% and 6% for the pollutant solutions of bovine serum albumin (BSA), SA, humic acid (HA) and mimetic sewage, respectively; while the IFR values of the neat PVDF membrane for all the pollutant solutions were higher than 30%. The fouled surface of the PVDF membrane suppressed the adsorption of hydrophobic pollutants due to the improved hydrophilicity, and prevented hydrophilic pollutants from entering the membrane pores due to hydrogen bonding, electrostatic and counterion effects. The higher water flux recovery ratios were observed because the pollutants were withheld on the modified membrane surface due to the cake layer feature of SA, and could be eliminated by simple flushing, leading to less irreversible fouling. The purpose of this article is to provide a novel and effective antifouling mechanism for the solution of the membrane fouling problem in sewage treatment.