To retain the hydroxyl group of poly(vinyl alcohol) (PVA), ammonium persulfate (APS) was used to initiate the polymerization of hydrogen on the PVA chain. Rather than hydroxyl-based cross-linking, the generated PVA macromolecule radicals were cross-linked with N,N′-methylene bisacrylamide (MBA) to prepare PVA membranes. The PVA membranes were shown to be successfully cross-linked via FT-IR characterization, as well as measurements of swelling degree and gel fraction. With increasing the content of cross-linker, the swelling degree of the membranes decreased, and the gel fraction increased. The pervaporation performance of the membrane was investigated by separating 95 wt% ethanol aqueous solutions. The cross-linked PVA membrane containing 0.5 wt% cross-linker yielded a high permeate water content (99 wt%) and a total flux of 353 g m⁻² h⁻¹ at 40 °C. As the feed temperature increased, the total flux increased, while the permeate water content decreased. The cross-linked membrane exhibited good durability over long-term operation.