Using　geometrical　optics,　a　laser　beam　homogenizer　for　high　power　CO2　has　been　designed.　Laser　beam　is　homogenized　by　means　of　waveguide,　separate　beam　with　spectroscope,　so　the　device　can　be　used　to　sintering　ceramics　on　double　sides.　The　waveguide　is　composed　of　a　square-section　tube　with　four　flat　rectangular　mirrors,　and　its　length　is　200　mm,　cross　section　10　mm10　mm.　Two　mirrors　that　has　an　angle　with　each　other　forms　the　spectroscope.　The　uniformity　of　the　power　distribution　is　stable　without　being　affected　by　original　laser　beam.　Using　Fourier　optics　to　analyze　system,　the　method　to　improving　the　uniformity　has　been　discussed.　Because　all　the　elements　have　reflecting　surface,　energy　loss　is　not　serious,　optical　path　adjusting　is　convenient.