Bioinspired　coordination　chemistry　is　a　powerful　platform　in　regulating　interfacial　interactions　for　manufacturing　antifouling　oil–water　separation　membranes.　Herein,　we　propose　a　single-step　nonsolvent-induced　phase　separation　(NIPS)　method　enhanced　by　a　metal-polycarboxylic　acid　coordination　strategy　to　prepare　antifouling　hollow　fiber　membranes　(HFMs).　During　the　NIPS,　an　in　situ　coordination　reaction　occurred　between　1,2,4,5-cyclohexane　tetracarboxylic　acid　(CTA)　in　casting　bath　and　Fe3+　in　coagulation　solution.　This　reaction　leads　to　the　formation　of　coordination　networks　that　are　anchored　onto　the　membrane　interface.　The　assembly　of　coordination　networks　attenuated　surface　energy　while　physicochemical　properties　of　the　surface　and　pore　were　regulated　by　in　situ　coordination-enabled　interfacial　assembly,　synergistically　optimizing　both　permeability　and　antifouling　capability.　Due　to　steric　and　energetic　barriers,　the　nano-ridge　structures　assembled　at　the　interface　imparted　underwater　super-oleophobic　characteristics　to　the　membrane.　The　optimized　membrane　efficiently　separated　oily　emulsion　with　a　stable　permeance　of　367　L　m−2h−1　bar−1,　which　was　2.4　times　that　of　the　control,　and　its　rejection　exceeded　99.9　%.　The　metal-polycarboxylic　acid　coordination　self-assembly　method　will　bring　significant　promise　for　advancing　antifouling　HFMs　and　broadening　their　application　potential.　©　2025　Elsevier　B.V.