Predictions　of　coupled　conduction-radiation　heat　transfer　processes　in　periodic　composite　materials　are　important　for　applications　of　the　materials　in　high-temperature　environments.　The　homogenization　method　is　widely　used　for　the　heat　conduction　equation,　but　the　coupled　radiative　transfer　equation　is　seldom　studied.　In　this　work,　the　homogenization　method　is　extended　to　the　coupled　conduction-radiation　heat　transfer　in　composite　materials　with　periodic　microscopic　structures,　in　which　both　the　heat　conduction　equation　and　the　radiative　transfer　equation　are　analyzed.　Homogenized　equations　are　obtained　for　the　macroscopic　heat　transfer.　Unit　cell　problems　are　also　derived,　which　provide　the　effective　coefficients　for　the　homogenized　equations　and　the　local　temperature　and　radiation　corrections.　A　second-order　asymptotic　expansion　of　the　temperature　field　and　a　first-order　asymptotic　expansion　of　the　radiative　intensity　field　are　established.　A　multiscale　numerical　algorithm　is　proposed　to　simulate　the　coupled　conduction-radiation　heat　transfer　in　composite　materials.　According　to　the　numerical　examples　in　this　work,　compared　with　the　fully　resolved　simulations,　the　relative　errors　of　the　multiscale　model　are　less　than　13%　for　the　temperature　and　less　than　8%　for　the　radiation.　The　computational　time　can　be　reduced　from　more　than　300　h　to　less　than　30　min.　Therefore,　the　proposed　multiscale　method　maintains　the　accuracy　of　the　simulation　and　significantly　improves　the　computational　efficiency.　It　can　provide　both　the　average　temperature　and　radiation　fields　for　engineering　applications　and　the　local　information　in　microstructures　of　composite　materials.