Recently,　recycling　of　severely　contaminated　Nd-Fe-B　sintered　magnets　sludge　had　drawn　considerable　attention　due　to　the　concern　of　environmental　burden　and　high　cost　of　traditional　wet　process　recycling.　In　the　present　study,　we　describe　a　new　technology　that　utilizes　distillation,　reduction-diffusion　(RD),　and　nanoparticle-doping　techniques　to　prepare　recycled　Nd-Fe-B　sintered　magnets　from　Nd-Fe-B　sludge　in　an　efficient　and　environmentally　friendly　way.　The　sludge　was　purged　first　to　remove　both　organic　impurities　and　nonmagnetic　impurities.　The　purged　products　were　then　treated　with　calcium-assisted　RD　reaction　to　obtain　Nd2Fe14B　single-crystalline　powders.　After　doping　with　NdHx　or　DyHx　nanoparticles,　the　powders　were　fabricated　into　recycled　Nd-Fe-B　sintered　magnets　by　the　conventional　sintering　method.　The　recycled　magnets　bear　comparable　magnetic　properties　to　the　original　magnets.　With　10%　doping　of　NdHx　the　energy　product　of　the　original　magnets　is　recovered　by　88%;　with　15%　doping　of　DyHx,　the　coercivity　of　the　recycled　magnets　increases　by　34%　compared　to　the　original　magnets.　Furthermore,　comparison　between　the　conventional　recycling　method　and　our　new　technology　demonstrates　that　our　new　technology　is　an　economical　and　environmentally　friendly　strategy　for　sintered　Nd-Fe-B　sludge　recycling.