A　functional　stainless　steel　microextraction　fiber　easily　prepared　by　in　situ　growing　metal–organic　framework　UiO-66　was　presented　and　used　for　high-performance　analysis　of　polycyclic　musks.　Via　the　robust　Ag-SH　bonding　reaction,　mercaptoacetic　acid　was　easily　anchored　on　Ag　film　to　provide　carboxyl　group　on　the　stainless　steel　fiber,　then　in　situ　grown　UiO-66　was　fulfilled　via　the　coordination　reaction　between　Zr4+　and　carboxyl　group.　Good　characteristics　including　large　surface　area,　high　thermal　stability,　and　good　adsorption　property　were　achieved.　Sensitive　detection　limits　(0.015–0.040 ng/L)　were　achieved　for　polycyclic　musks　by　coupling　with　gas　chromatography　with　mass　spectrometry,　and　it　could　be　stable　enough　for　150　extraction　cycles　without　a　significant　loss　of　extraction　efficiency.　Compared　with　the　classical　commercial　fibers,　2.2–11.4　times　higher　enhancement　factors　were　shown.　Applied　to　the　analysis　of　fortified　river　water　samples,　five　typical　polycyclic　musks　were　well　detected　with　the　recoveries　of　90.2–101.8%,　respectively.　It　showed　a　facile　approach　for　preparing　stainless　steel　microextraction　fiber　via　chemically　bonding　in　situ　grown　metal–organic　framework　for　high-performance　enrichment.　©　2020　WILEY-VCH　Verlag　GmbH　&　Co.　KGaA,　Weinheim