An　environmentally　friendly　adsorbent　for　recovering　nuclear　energy　source　U(VI)　from　wastewater　plays　a　crucial　role　in　resource　recovery　and　environmental　preservation.　In　this　work,　a　double-network　aerogel　adsorbent　composite　constructed　from　sodium　alginate,　poly(acrylic　acid),　and　NH2-MIL-125　(NM@SA)　was　fabricated　by　a　mild　method,　which　was　adopted　to　remove　and　concentrate　U(VI)　in　the　corresponding　simulated　wastewater　samples.　According　to　the　results　of　adsorption　kinetic　and　isotherm　models,　the　adsorption　of　U(VI)　on　NM@SA　was　a　monolayer　chemisorption　process.　The　maximum　adsorption　capacity　of　NM@SA　for　U(VI)　calculated　from　the　Langmuir　model　was　703.6　mgg(-1).　In　addition,　the　adsorbent　maintained　excellent　adsorption　capacity,　recoverability,　and　reuse　in　large-scale　operation.　The　same　abilities　can　be　demonstrated　in　real　seawater　environments.　Finally,　the　potential　adsorption　mechanisms　of　U(VI)　on　NM@SA　were　discussed　in　conjunction　with　the　experimental　determination　and　characterization　results.　Overall,　this　study　introduces　an　advantageous　research　approach　for　treating　U(VI)-containing　radioactive　wastewater.