How　to　treat　uranium-containing　wastewater　effectively　by　adsorption　and　recycle　waste　adsorbent　is　an　agent　problem　affecting　the　sustainable　development　of　nuclear　energy.　This　study　successfully　developed　a　superhydrophilic　nano-MgO　biochar　(MBC)　for　the　efficient　and　selective　separation　of　UO22+　and　mineralization　recycle　of　waste　MBC.　The　optimum　operating　parameters,　kinetics,　isotherms,　thermodynamics　and　adsorption　selectivity　of　adsorption　by　MBC,　were　studied.　The　adsorption　kinetics　was　well　characterized　by　the　Elovich　model　and　the　adsorption　isotherm　was　well　fitted　by　the　Langmuir-Freundlich　model.　The　adsorption　process　was　spontaneous　and　endothermic.　The　selectivity　test　results　showed　that　MBC　had　outstanding　selectivity　and　efficiency　for　UO22+　in　high　concentration　coexisting　ion　solution.　The　predominant　adsorption　mechanism　of　UO22+　by　MBC　was　MgU2O7　microprecipitation　mechanism,　and　the　mineralization　recycle　of　UO22+　is　a　feasible　recovery　method　for　uranium.