A　rapid　and　facile　approach　was　developed　for　the　synthesis　of　core-shell　structured　magnetic　covalent　organic　framework　nanobeads　by　using　the　monodisperse　Fe3O4　nanoparticles　(NPs)　as　magnetic　core,　and　1,3,5-triformylbenzene　(Tb)　and　benzidine　(Bd)　as　two　building　blocks　(denoted　as　Fe3O4@TbBd),　which　were　explored　as　an　adsorbent　for　magnetic　solid-phase　extraction　(MSPE)　of　estrogens　from　human　urine　sample.　The　core-shell　structured　Fe3O4@TbBd　nanobeads　showed　some　attractive　features　involving　high　specific　surface　area　(202.18　m2/g),　uniform　pore　size　distribution　(2.8　nm),　high　magnetic　responsivity　(41.4　emu/g),　as　well　as　excellent　thermal　and　chemical　stability,　which　made　it　an　ideal　adsorbent　for　selective　isolation　and　enrichment　of　estrogens.　Some　parameters　influencing　extraction　efficiency,　including　adsorbent　dosage,　extraction　time,　pH,　ion　strength,　desorption　solvent　and　desorption　time　were　investigated　systematically.　Combined　with　HPLC–MS,　a　simple,　fast,　and　sensitive　method　was　developed　for　the　enrichment　and　sensitive　determination　of　seven　estrogens,　which　showed　good　linearity　(r　>　0.9978)　in　the　range　of　0.005–10　μg/L,　low　limits　of　detection　(0.2–7.7　ng/L,　S/N　=　3),　low　limits　of　quantification　(0.6–25.6　ng/L,　S/N　=　10),　high　enrichment　factors　(75–197　fold),　and　good　precision　with　relative　standard　deviations　(RSD)　lower　than　4.8%　for　intra-day　and　6.7%　for　inter-day.　The　proposed　method　was　successfully　applied　to　the　analysis　of　trace　estrogens　in　urine　sample　of　pregnant　woman　with　good　recoveries　(80.6–111.6%),　demonstrating　the　promising　potential　of　the　Fe3O4@TbBd　nanobeads　as　adsorbent　in　sample　pretreatment.　©　2018　Elsevier　B.V.