Nanofillers　are　frequently　used　to　improve　the　mechanical　properties　of　hydrogels,　but　it　is　still　difficult　to　develop　composite　hydrogels　with　simultaneously　enhanced　strength,　fracture　strain,　toughness　and　fatigue　threshold　at　a　high　water　content.　Inspired　from　the　unique　structure　of　spider　silk,　we　propose　a　＇macromolecular　chain　engineered　aramid　nanofiber　(ANF)　reinforcement＇　strategy　to　prepare　strong　and　fatigue　resistance　hydrogels　with　a　relatively　high　water　content.　ANFs　can　decrease　the　crystallinity　while　increase　the　stretchability　of　PVA　hydrogels.　The　stress　can　be　effectively　transferred　from　the　soft　and　ductile　polymer　chains　to　the　hard　and　strong　ANFs　through　strong　interfacial　hydrogen　bonding.　The　tensile　strength,　fracture　strain,　toughness　and　fracture　energy　of　ANF　reinforced　hydrogels　(ARHs)　can　reach　as　high　as　2.07　±　0.15　MPa,　1084　±　116　%,　12.66　±　1.1　MJ　m−3,　and　3196　±　219　J　m−2,　respectively,　at　a　water　content　of　∼80　%.　Also,　ARHs　show　great　crack　propagation　resistance　with　the　fatigue　threshold　up　to　∼157　J　m−2.　The　bioinspired　ARHs　with　outstanding　mechanical　properties　and　anti-swelling　performance　have　promising　applications　in　the　field　of　soft　underwater　robots,　artificial　muscles,　and　so　on.　©　2024　Elsevier　Ltd