The　molybdenum　powder　doped　with　rare　earth　oxide　was　processed　by　powder　metallurgy　method　and　a　new　style　thin　film　cathode　material　was　firstly　processed　by　Spark　Plasma　Sintering　(SPS)　method　in　this　paper.　The　secondary　emission　property　of　such　kind　of　cathode　materials　were　studied,　the　maxim　secondary　emission　coefficient　after　the　material　was　activated　at　1600°C　reached　to　3.84　about　double　that　of　traditional　cathode　materials　application　in　magneto.　The　microstructure,　element　analysis　and　phase　constitution　of　materials　before　and　after　the　secondary　emission　property　was　measured　were　studied　through　SEM,　EDAX　and　XRD.　The　results　show　that　a　rare　earth　layer　about　5um　thickness　was　created　after　the　material　was　activated　at　1600°C.　The　material　grain　size　is　about　1　um　or　even　smaller　and　the　distribution　of　elements　in　such　materials　is　even.