The　high　injected　electron　concentration　and　low　work　function　C12A7:e-　was　successfully　prepared　by　the　solgel　method　combined　with　spark　plasma　sintering(SPS)　using　calcium　nitrate,　aluminum　nitrate,　citric　acid,　and　ethylene　glycol　as　raw　materials.　By　analyzing　the　morphology　of　carbon　and　its　role　in　the　reactive　synthesis,　we　reveal　the　reaction　synthesis　mechanism　of　C12A7:e-　under　the　SPS.　The　analysis　shows　that　C12A7:e-　started　to　be　generated　at　800　degrees　C.　During　the　SPS　reaction　sintering　process,　carbon　atoms　from　citric　acid　and　ethylene　glycol　were　excited　by　a　pulsed　current　at　high　temperature,　forming　the　carbon　ions　C22-　and　C　(gas).　Both　act　as　reducing　agents　and　react　with　the　free　oxygen　ions　O2-　in　the　C12A7　cage　cavity　to　form　gaseous　CO　or　CO2,　enabling　electrons　to　be　injected　into　the　cage　cavity,　thus　generating　C12A7:e-.　Meanwhile,　the　graphene　oxide　(GO)　formed　on　the　surface　of　C12A7:e-　grain　is　produced　by　the　precursor　of　sol-gel　synthesis　in　the　high　temperature　oxidation　environment,　which　will　be　conducive　to　improving　the　stability　of　C12A7:　e-　in　air　and　high　temperature　oxidation　resistance.