Mussel-inspired　polydopamine　(PDA)　coating　has　received　increasing　interest　in　membrane　modification　for　versatile　liquid　filtration　applications,　due　to　its　intrinsic　adhesion　nature.　Nevertheless,　the　bio-inspired　PDA　deposition　initiated　by　air-oxidation　is　time-consuming　process　and　generally　results　in　an　uneven　and　unstable　coating,　which　compromises　the　membrane　filtration　performance.　In　this　study,　the　PDA/polyethylenimine　(PEI)　co-deposition　triggered　by　ammonium　persulfate　(APS)　was　conducted　to　fabricate　the　tight　ultrafiltration　(t-UF)　membranes　with　1000–5000　Da　molecular　weight　cut-offs　(MWCOs)　for　sustainable　treatment　of　highly-saline　textile　wastewater.　APS　with　strong　oxidation　capacity　can　rapidly　induce　the　co-deposition　of　PDA/PEI　layer　onto　hydrolyzed　polyacrylonitrile　(HPAN)　substrate　through　the　Michael　addition　or　Schiff　base　reactions,　simultaneously　minimizing　the　covalent　polymerization　of　dopamine　for　PDA　aggregation.　With　1.5-h　coating,　a　smooth,　compact　and　defect-free　PDA/PEI　layer　with　1700　Da　MWCO　was　evolved　on　the　HPAN　substrate,　evincing　a　＞98.2%　retention　for　various　reactive　dyes　(610–1000　Da　molecular　weights)　with　＞97.0%　permeation　of　inorganic　salts.　In　addition,　an　integrated　UF-diafiltration　procedure　was　applied　to　fractionate　the　reactive　blue　4　(RB4)/NaCl　and　RB4/Na2SO4　mixtures,　enriching　the　RB4　dye　from　ca.　2.04　to　50.70　g·L−1　with　ca.　99.95%　desalination　efficiency　and　ca.　99.2%　dye　recovery.　These　results　demonstrate　that　the　bio-inspired　t-UF　membrane　through　fast　PDA/PEI　co-deposition　is　of　great　promise　to　sufficiently　fractionate　the　dyes　and　salts　for　dye　desalination　and　recovery,　realizing　the　sustainable　management　of　highly-saline　textile　wastewater.　©　2019　Elsevier　B.V.