Based　on　electromagnetic　scattering　theory,　Mie　scattering　theory　and　Monte　Carlo　method　are　used　to　analyze　the　radiation　characteristics　of　SiC　particles　with　different　distribution　forms.　The　radiation　characteristics　of　different　particle　size　distributions　were　obtained　by　simulation.　The　results　shows　that　the　form　of　particle　size　distribution　has　a　significant　impact　on　the　spectral　transmittance　of　particle　swarms.　The　proportion　of　particles　of　different　sizes　in　the　distribution,　the　dispersion,　and　the　span　of　particle　size　scale　all　affect　the　infrared　extinction　performance　of　particle　swarms　in　varying　degrees.　Among　them,　the　proportion　of　particles　of　specific　size　is　the　most　influential　factor,　which　is　a　necessary　factor　to　ensure　the　existence　and　amplitude　of　particle　characteristic　spectra.　The　relationship　between　particle　size　distribution　and　radiation　characteristics　was　also　analyzed　by　static　and　dynamic　infrared　spectroscopy,　which　showed　that　increasing　the　proportion　of　particles　in　the　0.16　similar　to　2.5　mu　m　particle　size　range　of　SiC　particle　swarm　can　comprehensively　improve　their　extinction　performance.