To　further　optimize　the　comprehensive　magnetic　properties　of　LaCe-based　sintered　magnets　prepared　by　constructing　a　multi-main-phase　(MMP)　structure,　Pr-Fe-B　was　used　as　a　LaCe-free　alloy　to　prepare　MMP　sintered　magnets　with　40　wt%　LaCe　substitution.　Due　to　the　high　anisotropy　field　(H-A)　of　Pr2Fe14B　grains,　strong　chemical　heterogeneity　could　be　provided　in　MMP　magnets.　In　addition,　the　Pr-rich　phase　with　a　lower　melting　point　enters　the　MMP　magnet,　optimizing　the　composition　and　structure　of　the　grain　boundary　(GB)　phase.　It　is　beneficial　to　improve　the　wettability　and　promote　the　formation　of　continuous　GB　layers.　As　a　result,　the　H-cj　and　(BH)(max)　of　the　MMP　magnets　reached　9.64　kOe　and　37.70　MGOe,　leading　to　an　excellent　overall　magnetic　performance　of　(BH)(max)　(MGOe)　+　H-cj　(kOe)　=　47.34.　This　will　serve　as　a　reference　for　the　high　performance　of　MMP　LaCe-based　magnets.