Membrane-based　micro-solid　phase　extraction　(M-μSPE)　has　garnered　great　attention　in　sample　pretreatment,　suffering　an　inherent　contradiction　between　permeability　and　adsorption　capacity.　In　this　study,　a　pure　microporous　organic　network　(TEB-DIB-MON)　fiber　membrane　was　prepared　by　combining　electrostatic　spinning　technology,　Sonogashira-Hagihara　reaction　and　template　sacrifice　method.　The　prepared　TEB-DIB-MON　membrane　exhibited　a　large　specific　surface　area　with　a　hollow　and　porous　structure,　thereby　providing　excellent　solvent　permeability　and　high　adsorption　capacity　for　okadaic　acid　(OA,　an　algal　toxin).　Under　the　optimized　conditions,　a　sensitive　analytical　method　was　established　by　coupling　M-μSPE　with　high-performance　liquid　chromatography-tandem　mass　spectrometry　(HPLC-MS/MS).　The　established　method　has　a　low　detection　limit　(0.5　pg　mL−1),　a　wide　linear　range　(1.5–1000　pg　mL−1,　R　≥　0.9991),　and　good　reproducibility　(RSD　≤　9.4　%,　n　=　6),　which　was　then　successfully　applied　for　OA　detection　in　marine　organisms.　Trace　amounts　of　OA　(59.3–89.0　pg　mL−1)　was　detected　in　the　oyster　and　prawn　samples.　This　work　demonstrated　that　the　excellent　application　potential　of　MON　membranes　in　sample　pretreatment,　while　also　presents　a　novel　synthesis　strategy　for　MONs　membranes.　©　2024　Elsevier　B.V.