Using polyester (PET) fabric scraps as the base membrane, the superhydrophilic hydrogel layer surface-modified PET fabric membrane (PET-HPAS) was prepared through ultraviolet light-induced surface grafting of glycidyl methacrylate (GMA), hybrid crosslinking with hyperbranched polyamide (HP), and aminated sodium lignosulfonate (LA). The modified polyester fabric membrane was characterized by FTIR, XPS, and SEM, and the according effects of GMA grafting ratio, LA and HP dosage on the hydrophilicity, pure water flux, and oil-in-water emulsion separation performance were investigated. The oil-water separation mechanism of the super-hydrophilic hydrogel layer-modified PET fabric membrane was also explored. The results showed that using a modified PET fabric membrane with a GMA grafting ratio of 21.68% as the substrate, and with HP and LA dosages of 0.60 g and 0.15 g, respectively, in the hybrid crosslinking grafting solution, the prepared super-hydrophilic PET-HPAS achieved a pure water flux of 183.1 L/(m2·h) under gravity alone, which was 1.4 times that of the original polyester fabric membrane. For surfactant-stabilized oil-in-water emulsions such as toluene, n-hexane, and petroleum ether, the PET-HPAS demonstrated excellent separation and purification performance, with permeation fluxes of 165.1, 150.2, 100.2 L/(m2·h), respectively, and separation efficiencies all exceeding 99%, outperforming previously reported modified PET fabric separation membranes. Moreover, the PET-HPAS fabric membrane exhibited good reusability.