We　propose　an　effective　and　rapid　route　for　synthesizing　polycrystalline　mayenite　electride　(C12A7:e(-))　in　dense　bulk.　C12A7:e(-)　bulks　with　high-density　electron　doping　were　obtained　via　a　comprehensive　method,　which　combined　Ti　powder　treatment　with　spark　plasma　sintering　(SPS)　process　under　a　10(-2)Pa　vacuum.　The　resulting　electride,　which　exhibits　an　electron　concentration　of　similar　to　2.3　x　10(21)cm(-3),　an　electrical　conductivity　of　similar　to　1.38　x　10(3)S/cm　at　300　K,　and　an　absorption　peak　at　2.5eV,　was　obtained　via　SPS　process　at　1150　degrees　C　for　20　min.　Furthermore,　thermionic　emission　from　a　flat　surface　of　C12A7　electride　was　examined　at　temperatures　of　973-1373　K　and　acceleration　electrical　field　of　3000-35000　V/cm　in　a　10(-5)　vacuum.　A　large　current　density　of　1.68　A/cm(2)　was　obtained　in　the　thermionic　emission　with　an　work　function　(phi(wp))　of　2.13eV　for　an　applied　electric　field　of　35000　V/cm.　Moreover,　the　emission　with　a　current　density　of　1.68　A/cm(2)　was　stably　sustained　for　30　h.　These　results　not　only　suggest　an　efficient　method　for　fabricating　high-quality　mayenite　electrides　but　also　pave　a　way　for　various　applications　including　thermionic　emission.