Large-size　and　high-quality　single-crystal　GdB(6)conductive　ceramics　(length　greater　than　35　mm　and　diameter　greater　than　6　mm)　were　prepared　by　optical　zone　melting,　and　the　single-crystal　quality　was　characterized　by　single-crystal　diffraction,　Laue　photo,　crystal　plane　rocking　curve,　and　single-crystal　fracture　scan.　Electrochemical　corrosion　equipment　of　single-crystal　GdB(6)conductive　ceramic　tips　was　newly　designed,　which　greatly　reduced　the　preparation　time　of　tips　from　more　than　10　h　to　2.75　h.　The　field　electron　emission　current　density　of　the　single-crystal　GdB(6)conductive　ceramic　tip　(r　approximate　to　500　nm)　prepared　by　the　device　under　applied　voltage　(2550　V)　is　2.24　x　10(4)A/cm(2).　This　paper　also　theoretically　calculates　the　electronic　structure　and　electron　work　function　of　single-crystal　GdB(6)under　a　strong　electric　field　(0.1　V/angstrom).　The　trapping　ability　of　the　B-octahedron　in　the　single　crystal　GdB(6)conductive　ceramics　against　the　free　electrons　of　Gd　is　greatly　weakened　under　a　strong　electric　field　(0.1　V/angstrom),　and　the　free　electrons　also　have　a　certain　enrichment　phenomenon　on　the　surface　of　GdB6.　The　surface　barrier　of　single-crystal　GdB(6)conductive　ceramic　will　be　shortened　and　narrowed　sharply　due　to　the　strong　electric　field　(0.1　V/angstrom),　which　causes　the　work　function　of　(100)　crystal　plane　of　single-crystal　GdB(6)to　decrease　sharply　(0.38　eV).　This　causes　the　free　electrons　in　Gd　to　have　greater　energy　at　the　time　of　emission,　and　it　is　easier　to　get　rid　of　the　trap　of　surface　barriers,　which　is　conducive　to　field　electron　emission.