A　field-emission　microtips　array　with　a　radius　of　curvature,　height,　and　separation　distance　of　0.5,　5,　and　4　mu　m,　respectively,　was　processed　on　the　single-crystal　Gadolinium　hexaboride　ceramic　(GdB6)　(100)　plane　using　a　femtosecond　laser.　The　height　and　morphology　of　the　microtips　array　were　uniform,　and　the　crystal　structure　and　phase　composition　of　GdB6　did　not　change　after　the　processing.　According　to　the　field-emission　performance　test　of　a　GdB6　microtips　array,　the　turn-on　electric　field　intensity　was　1.9　V/mu　m,　and　the　field-emission　current　density　reached　0.49　A/cm(2)　when　the　applied　electric　field　strength　was　6.7　V/mu　m;　meanwhile,　it　had　outstanding　field-emission　stability.　Subsequently,　the　transmission　process　of　the　field-emission　current　of　the　GdB6　between　the　cathode　and　the　anode　was　simulated　using　COMSOL　Multiphysics　5.6　software.　The　transmission　process　of　the　electron　beam　from　emitters　to　the　anode　surface　was　divided　into　three　stages　due　to　the　interaction　between　emission　electrons　and　a　magnetic　field　generated　by　its　motion,　including　divergence,　pinch,　and　drift.　The　increase　of　electric　field　strength　reduced　the　radial　displacement　of　the　electron　beam　while　moving　the　beam　waist　further　away　from　the　anode　surface.　The　simulation　results　provide　theoretical　guidance　for　regulating　the　shape　of　the　field-emission　electron　beam,　size,　and　energy.