To address the issues of easy loss and poor loading stability of PF₆⁻-based ionic liquids in catalytic oxidative desulfurization, this study proposes a strategy of “carrier modification-particle functionalization-composite construction.” Using polyacrylonitrile (PAN) nanofiber membrane as the carrier, a lipophilic PAN-C₈ membrane was prepared via alcoholysis modification. Subsequently, amino-functionalized PF₆⁻-polyionic liquid (PIL-PF₆) Janus particles were synthesized through seeded emulsion polymerization and ion exchange technology, and finally, the PIL-PF₆ Janus@PAN-C₈ composite membrane was constructed. The catalytic oxidative desulfurization performance of the composite membrane for dibenzothiophene (DBT) was systematically investigated. Results showed that under the conditions of 60℃, oil-to-agent ratio of 150:1, and H₂O₂ as oxidant, the PW-5 catalyst with the highest PF₆⁻ content achieved a desulfurization rate of 99.55% after 4 hours of reaction. The composite membrane exhibited excellent stability and reusability. This material integrates “adsorption-catalysis-separation” in one, providing a new technical path for the efficient treatment of sulfur-containing pollutants.