Through　setting　the　thermal　test　points　on　section　of　concrete　filled　steel　tubular　(CFST)　truss　arch　and　the　mini　weather　stations　on　site,　the　thermal　field　test　on　section　of　CFST　truss　arch　rib　and　the　meteorological　data　collection　were　carried　out.　The　temperature　distributions　of　chord　member　were　analyzed.　The　average　temperatures　and　the　corresponding　thermal　stresses　were　also　analyzed　by　finite　element　method.　The　result　shows　that　temperature　distributions　of　top　and　bottom　chord　members　are　similar　in　the　series　which　is　parallel　to　the　direction　of　sun＇s　movement,　temperature　distributions　of　the　left　and　right　chord　members　are　similar　in　the　series　which　is　perpendicular　to　the　direction　of　sun＇s　movement.　The　temperature　distribution　and　the　average　temperature　of　each　chord　member　are　similar　to　those　of　the　singular　circular　tube.　In　consideration　of　simply　analysis,　the　thermal　field　of　singular　circular　tube　can　be　used.　The　average　temperature　of　each　chord　member　is　similar　so　that　the　thermal　stress　caused　by　the　average　temperature　difference　of　each　chord　member　is　too　little　to　be　neglected.　The　thermal　stresses　of　chord　member　and　the　web　member　are　little　influenced　by　the　temperature　difference　of　the　two　members　which　can　be　neglected　in　calculation.