Nanostructured　multi-main-phase　(MMP)　Nd-Ce-Fe-B　magnet　produced　by　melt-spinning　powders　has　great　potential　for　achieving　high　performance.　However,　the　inferior　intrinsic　properties　of　the　Ce2Fe14B　phase　lead　to　the　low　coercivity　and　thermal　stability　of　this　magnet.　In　this　study,　low-melting-point　Pr68Cu32　powders　were　introduced　into　nanostructured　MMP　magnet　through　intergranular　addition　to　further　improve　its　coercivity　H-cj　and　thermal　stability.　When　only　2　wt%　Pr(68)Cu(32　)was　added,　the　intrinsic　coercivity　and　thermal　stability　were　significantly　improved　with　a　slight　reduction　in　the　remanence　B-r　and　the　maximum　energy　product　(BH)(max).　The　microstructure　evolution　of　MMP　magnet　with　adding　Pr(68)Cu(32　)was　revealed　by　microstructural　and　compositional　characterization　and　thermodynamic　calculation,　and　a　schematic　model　was　proposed.　Furthermore,　mechanisms　underlying　changes　in　magnetic　properties　were　systematically　analyzed　by　combining　micromagnetic　simulation.　(C)　2020　Elsevier　B.V.　All　rights　reserved.