The　constant　wall　flux　boundary　condition　in　computational　fluid　dynamics　coupled　with　the　discrete　element　method　(CFD-DEM)　remains　unresolved　and　there＇s　no　well-acknowledged　method　at　present.　A　numerical　approach　to　deal　with　constant　wall　flux　boundary　condition　in　a　fluidized　bed　by　CFD-DEM　is　proposed　in　the　present　work,　which　allows　the　particle-wall　heat　flux,　fluid-wall　heat　flux,　and　wall　temperature　to　vary　with　space　and　time.　The　influences　of　the　both　fluid　phase　and　the　solid　phase　on　wall　temperature　are　taken　into　consideration.　The　present　model　is　compared　with　the　previous　method　proposed　by　Lattanzi　et　al.　Both　methods　are　tested　in　a　gas-solid　fluidized　bed.　The　effects　of　wall　heat　flux　and　velocity　are　considered.　The　wall-to-bed　heat　transfer　coefficients　by　the　present　method　agree　better　with　those　calculated　by　empirical　correlations　than　those　by　Lattanzi＇s　method,　which　indicates　that　the　present　method　is　more　accurate.　The　method　in　the　present　paper　provides　a　solution　to　the　constant　wall　flux　boundary　condition　in　a　fluidized　bed　by　CFD-DEM　and　can　be　extended　to　other　multiphase　systems.　©　2020　Elsevier　B.V.