Uranium　is　a　basic　and　strategic　resource　related　to　national　development　and　security.　The　uranium　resources　contained　in　the　ocean　are　thousands　of　times　that　in　the　land,　up　to　about　4.5　billion　tons.　However,　it　is　still　a　severe　challenge　for　the　extraction　of　uranium　from　seawater　as　it　contains　trace　amounts　of　uranium　and　a　large　number　of　cations.　Herein,　a　new　uranium　extraction　material,　phosphate-functionalized　collagen　fibers,　was　prepared　by　a　＇covalent　cross-linking＇　method　by　grafting　the　phosphate　functional　groups　onto　the　surface　of　collagen　fibers　(CF)　with　a　multihierarchy　structure　and　multiple　functional　groups.　The　special　structure　of　CF　makes　the　adsorbent　exhibit　multistage　kinetics　and　is　controlled　by　chemisorption　and　layer　diffusion.　Through　the　introduction　of　amino　and　phosphoric　acid　functional　groups,　collagen　fiber-alendronate　sodium　trihydrate　(CF-AST)　exhibits　high-efficiency　adsorption　for　uranium　with　the　maximum　adsorption　reaching　277.78　mg　g-1.　In　the　extraction　test　from　the　East　China　Sea,　CF-AST　displayed　a　total　uranium　extraction　mass　of　29.61　μg　after　processing　10　L　of　seawater　with　an　extraction　rate　of　89.69%.　This　adsorbent　has　shown　superiorities　in　selectivity,　kinetics,　capacity,　and　reproducibility　of　uranium　separation　and　enrichment　from　seawater,　which　is　an　economically　viable　and　industrially　scalable　realistic　uranium　extraction　material.　©　2022　American　Chemical　Society