The　work　aims　to　deeply　understand　the　thermal　shock　behavior　of　plasma　sprayed　8YSZ　thermal　barrier　coating　subjected　to　molten　aluminum.　Finite　element　numerical　simulation　was　carried　out　by　thermal-mechanical　coupling　method　in　transient　temperature　field　and　transient　stress　field　when　the　plasma　sprayed　8YSZ　thermal　barrier　coating　was　immersed　in　molten　aluminum,　and　effects　of　preheating　temperature　and　thickness　of　top　coat　on　stress　distribution　were　studied.　Through　calculation　of　temperature　field,　the　coating　surface　temperature　reached　up　to　a　molten　aluminum　temperature　as　the　coating　was　immersed　into　the　molten　aluminum　for　only　0.1　s.　Temperature　distribution　in　the　coating　changed　gradually　from　exponential　distributions　to　nearly　linear　distributions　as　the　immersion　time　increased,　but,　the　temperature　gradient　in　the　coating　decreased　as　the　immersion　time　increased.　The　stress　in　corresponding　coating　reached　up　to　the　maximum　in　a　short　time　and　the　maximum　stress　decreased　as　the　heating　time　increased.　As　preheating　temperature　of　the　coating　increased,　both　the　maximum　axial　stress　and　the　maximum　hoop　stress　in　the　top　coat　decreased,　and　effects　of　the　preheating　temperature　on　the　axial　stress　became　more　obvious.　As　the　top　coat　thickness　increased,　the　axial　stress　and　the　hoop　stress　in　the　top　coat　increased　accordingly,　but　all　the　stresses　decreased　in　the　bond　coat　(BC).　The　preheating　treatment　to　thermal　barrier　coating　can　effectively　reduce　the　thermal　stress　value　in　the　coating.　As　the　coating　thickness　increases,　the　stress　in　top　coat　and　bond　coat　respectively　increases　and　decreases　and　the　effect　of　top　coat　thickness　on　stress　in　bond　coat　is　more　obvious.　©　2018　Chongqing　Wujiu　Periodicals　Press.　All　rights　reserved.