Aiming　at　the　problem　of　heat　dissipation　of　electronic　devices　in　low　temperature　environment,　the　effect　of　thermal　conductivity　and　emissivity　of　coating　on　its　heat　dissipation　performance　was　studied　by　theoretical　calculations　and　experiments　in　this　study.　The　results　show　that　the　heat　dissipation　performance　of　organic　coating　with　emissivity　of　0.7-0.95　is　improved　as　its　thermal　conductivity　increasing.　And　temperature　difference　between　inside　and　surface　of　object　is　inversely　proportional　to　thermal　conductivity.　That　is,　when　thermal　conductivity　exceeds　a　certain　value,　it　will　no　longer　affect　heat　dissipation　performance　of　coating.　In　addition,　emissivity　of　coating　directly　affects　its　cooling　performance,　and　the　proper　matching　interaction　between　thermal　conductivity　and　emissivity　of　coating　can　enhance　heat　dissipation　effects.　In　the　case　of　non-forced　convection　cooling,　the　thermal　conductivity　of　the　organic　coating　is　preferably　2-10　W/m.K.