In the face of large amounts of oily wastewater generated by oil extraction and human activities, the development of efficient oil-water separation technology is an urgent requirement for ensuring ecological and environmental safety and the sustainable use of resources. Membrane separation technology has become one of the effective solutions for oily wastewater treatment due to its advantages of high efficiency and convenience. To improve the hydrophilic/oleophobic properties of hydrophobic separation membranes, this study employed polyvinylidene fluoride (PVDF) hydrophobic membranes with good mechanical properties as the substrate. Through a biomimetic coating method, dopamine (DA) was first polymerized to form polydopamine (PDA) on the surface of PVDF membranes, which then reacted with polyvinyl alcohol (PVA) to form a dense hydrophilic layer, thus preparing modified membranes with hydrophilic/oleophobic surface properties. The morphology and composition of the modified membranes were characterised by scanning electron microscopy (SEM), atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS). The oil-water separation performance of the modified membranes was comprehensively evaluated by determining the water contact angle, underwater oil contact angle, emulsion flux, and oil rejection. The results showed that the modified membrane M3, prepared under the optimal process conditions, achieved a pure water flux of 4893.2±70.2 L/(m2?h), an emulsion flux of 2138.1±29.4 L/(m2?h) for toluene-in-water emulsion, and an oil rejection of 98.5%±0.1%. Simulated fouling and regeneration tests using bovine serum albumin (BSA) solution indicated that the flux recovery rate of the M3 membrane reached 92.0%, exhibiting good antifouling performance. Immersion tests in acid, alkali, and salt solutions demonstrated that the modified membrane possessed excellent chemical stability. The PVDF modified membranes designed and prepared in this study exhibits the advantages of simplicity, environmental friendliness, and high efficiency, demonstrating excellent application potential in the field of oil-water separation. This work provides a new approach for the research and preparation of oil-water separation membranes.