Scandia　doped　tungsten　pressed　cathodes　were　prepared,　including　mixing　scandium　oxide　and　barium-calcium　aluminates　with　tungsten　by　different　powder　mixing　methods　combined　with　high　temperature　sintering　under　the　protection　of　hydrogen.　Experimental　results　show　that　mixing　uniformity　plays　important　roles　in　the　cathode　emission.　The　powders　prepared　by　ball-milling　have　small　particle　size　and　uniform　distribution　of　different　elements.　This　kind　of　powder　is　favorable　for　the　chemical　reaction　between　emission　salt　and　tungsten　to　take　place　fully　to　form　active　substance　which　could　improve　the　emission　property.　The　emission　current　density　of　the　cathode　prepared　with　ball-milling　powders　is　about　eight　times　higher　than　that　prepared　with　hand　mixing,　at　the　same　time,　four　times　higher　than　M-type　cathode.　During　the　activation　of　cathode,　the　surface　active　layer　containing　Ba,　Sc　and　O　is　established　due　to　the　simultaneous　diffusion　of　Ba,　Sc　and　O,　leading　to　the　improvement　of　emission　property.