Based　on　electromagnetic　scattering　mechanism,　Mie　scattering　theory　and　Monte　Carlo　method　are　used　to　analyze　the　radiation　characteristics　of　SiC　particle　swarm　with　different　distribution　forms　in　this　paper.　The　study　find　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　particle　size　distribution,　the　dispersion　of　particle　size　distribution,　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　in　the　particle　size　distribution　is　the　most　one,　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　deeply　analyzed,　and　the　results　showed　that　increasing　the　proportion　of　particles　within　the　0.16~2.5µm　particle　size　range　of　SiC　particle　can　comprehensively　improve　the　extinction　performance　of　SiC　particle　swarm,　which　is　of　practical　significance　for　optimizing　the　infrared　radiation　performance　of　particle　swarms.　©　2023　SPIE.