Designing　a　stable　and　uniform　hydrophilic　material　for　separation　of　oil　and　water　is　strongly　desired　for　sustainable　management　of　oily　wastewater.　Herein,　a　stable　and　uniform　bio-inspired　coating　onto　the　non-woven　fabric　substrate　with　superhydrophilicity　and　underwater　superoleophobicity　via　rapid　co-deposition　of　dopamine　and　polyethylenimine　was　demonstrated.　Ammonium　persulfate　outperformed　other　oxidants　(e.g.,　Cu2+-H2O2　and　NaIO4)　to　rapidly　trigger　the　co-deposition　of　dopamine　and　polyethylenimine　for　homogeneous　superhydrophilic　and　underwater　superoleophobic　surface　engineering.　Furthermore,　the　co-deposition　conditions,　i.e.,　concentration　of　ammonium　persulfate　and　exposure　duration,　have　a　positive　dependence　on　the　hydrophilicity　and　underwater　oleophobicity　of　the　coated　fabric　membranes.　Specifically,　the　superhydrophilicity　and　underwater　superoleophobicity　(underwater　oil　contact　angle　of　165.4　+/-　1.1　degrees,　sliding　angle　of　2.5　+/-　0.5　degrees)　can　be　obtained　for　the　coated　fabric　membranes　at　the　optimal　co-deposition　condition　(i.e.,　28.5　mmol　L-1　persulfate　and　coating　duration　of　7　h),　showing　a　great　potential　in　gravitational　oil-water　separation　(permeation　flux　＞115,000　L　m(-2)　h(-1);　oil　rejection　＞99.2%).　Integrating　with　a　superhydrophobic　copper　mesh,　the　oil-water　mixed　solution　can　be　continuously　and　sufficiently　separated,　realizing　simultaneous　recovery　of　pure　oil　and　water　from　oily　wastewater.　In　addition,　the　bio-inspired　coating　displays　a　strong　long-term　chemical　robustness　and　stability　in　extreme　environments　(i.e.,　acidic/alkaline　solutions　and　oils).　The　study　provides　a　facile,　cost-effective　and　practical　strategy　in　constructing　superhydrophilic　and　underwater　superoleophobic　interfaces　for　sustainable　treatment　of　oily　wastewater.