Scandia　pressed　cathodes　were　prepared　by　powder　metallurgy　method　using　mixed　powder　of　scandia　doped　tungsten　and　barium-calcium　aluminates　obtained　by　different　mixing　methods.　The　element　distribution　uniformity　greatly　affected　the　emission　property.　The　powder　prepared　by　ball-milling　had　small　particle　size　and　uniform　distribution　of　different　elements.　This　kind　of　powder　was　favorable　for　the　chemical　reaction　among　Ba,　Ca　aluminates,　scandia　and　tungsten　to　take　place　sufficiently　to　form　active　substance　which　can　improve　the　emission　property.　The　emission　current　density　of　the　cathode　prepared　with　ball-milling　powder　was　about　8　times　higher　than　that　prepared　by　manually　mixing　method,　4　times　higher　than　Os　coated　M-type　cathode.　The　higher　content　of　the　active　substance　on　the　cathode　surface　prepared　by　ball-milling　led　to　the　better　emission　performance　of　the　cathode.