This　work　proposed　a　sand-milling　method　to　prepare　nano　diffusion　sources　and　optimized　the　process　of　electrophoretic　deposition　and　sintered　Nd-Fe-B　grain　boundary　diffusion.　The　optimal　sand-milling　process　parameters　were　explored,　the　quality　of　electrophoretic　coating　was　improved　and　high-performance　magnets　were　obtained.　By　optimizing　the　entire　process,　the　utilization　of　heavy　rare　earth　resources　has　been　achieved.