Based　on　the　establishment　of　the　original　and　improved　models　of　the　turbine　blade,　a　thermal-fluid-solid　coupling　method　and　a　finite　element　method　were　employed　to　analyze　the　internal　and　external　flow,　temperature,　and　thermal　stress　of　the　turbine　blade.　The　uneven　temperature　field,　the　thermal　stress　distribution　characteristics　of　the　composite　cooling　turbine　blade　under　the　service　conditions,　and　the　effect　of　the　thickness　of　the　thermal　barrier　coating　(TBC)　on　the　temperature　and　thermal　stress　distributions　were　obtained.　The　results　show　that　the　method　proposed　in　this　paper　can　better　predict　the　ablation　and　thermal　stress　damage　of　turbine　blades.　The　thermal　stress　of　the　blade　is　closely　related　to　the　temperature　gradient　and　local　geometric　structure　of　the　blade.　The　inlet　area　of　the　pressure　side-platform　of　the　blade,　the　large　curvature　region　of　the　pressure　tip　of　the　blade,　and　the　rounding　between　the　blade　body　and　the　platform　on　the　back　of　the　blade　are　easily　damaged　by　thermal　stress.　Cooling　structure　optimization　and　thicker　TBC　thickness　can　effectively　reduce　the　high　temperature　and　temperature　gradient　on　the　surface　and　inside　of　the　turbine　blade,　thereby　reducing　the　local　high　thermal　stress.