In　optimizing　the　trade-off　between　power　density　and　phosphoric　acid　(PA)　retention　in　PA-doped　polybenzimidazole　(PA-PBI)　membrane　for　improving　performance　of　high-temperature　proton　exchange　membrane　fuel　cells　(HT-PEMFCs),　the　self-reinforcing　network　of　interfacial　interactions　of　the　HT-PEMs　has　to　be　deeply　investigated.　In　this　paper,　a　breakthrough　strategy　employing　a　quaternary　ammonium　(QA)-functionalized　porous　aromatic　framework　(QPAF-225)　to　synergistically　integrate　with　sulfonated　poly[2,2′-(p-oxydiphenylene)-5,5′-bibenzimidazole]　(SOPBI)　to　form　the　robust　HT-PEM　is　successfully　developed.　The　ionic　interactions　between　the　cationic　QA　moieties　and　anionic　sulfonic　acid　groups　can　establish　a　self-reinforcing　proton-conductive　network,　while　the　high-density　basic　sites　in　QPAF-225　act　as　the　PA　reservoirs　and　can　mitigate　the　leakage.　When　benchmarked　against　QA-deficient　PAF-225–10　(10%　PAF-225　in　composite　membrane)　composite　HT-PEMs　and　pristine　SOPBI,　the　QPAF-225–10　composite　delivers　a　high　proton　conductivity　of　174　mS　cm−1　at　200 °C　and　extremely　high　peak　power　density　of　847 mW　cm−2　of　the　HT-PEMFC　under　ultralow　Pt/C　loading　(0.3 mg　cm−2)　at　200 °C　operation,　which　surpasses　most　of　PA-PBI　systems　reported　in　literatures.　Critically,　such　a　membrane　exhibits　ultralow　voltage　decay　rate　(0.04 mV　h−1　over　904 h　at　200 °C)　and　high　PA　retention　ability,　coupled　with　mechanical　robustness　exceeding　industrial　durability　thresholds.　This　work　transcends　conventional　additives　by　exploiting　porous　aromatic　framework-mediated　proton　channels　and　PA-philic　motifs,　establishing　a　material　paradigm　for　next-generation　HT-PEMs　that　reconciles　high-power　operation　with　long-term　stability　in　harsh　electrochemical　environments.　©　2025　Wiley-VCH　GmbH.