In　the　paper,　coupling　calculation　of　conduction,　convection　and　surface　radiation　in　hollow　brick　walls　can　be　effectively　deal　with　by　original　computation　code.　The　equivalent　thermal　conductivity　of　hollow　brick　walls　have　been　predicted　numerically　under　exterior　insulation　condition.　The　change　of　equivalent　thermal　conductivity　of　hollow　brick　of　different　hole　number　and　arrangement　under　exterior　insulation　has　been　observed　to　emphasis　the　influence.　The　simulation　results　provide　valuable　data　for　the　hollow　brick　design　under　exterior　insulation.