In　deep　underground　engineering　projects,　such　as　tunnel　excavation　and　geothermal　resource　development,　flawed　rock　masses　frequently　experience　high-temperature　(HT)　and　high-pressure　environments.　Understanding　how　intermediate　principal　stress　(σ2)　affects　the　mechanical　behaviors　and　failure　characteristics　of　thermally　cycled　flawed　granite　is　intrinsically　crucial.　This　study　explores　the　correlations　among　the　strength,　acoustic　emission　and　failure　characteristics　in　thermally　cycled　flawed　granite　under　biaxial　compression　with　varying　σ2.　Results　show　that　for　a　given　temperature,　the　rock　strength　gradually　increases　as　σ2　increases,　but　the　σ2-dependency　of　strength　approaches　a　critical　state　when　σ2　attains　a　threshold.　Notably,　flawed　granite　subjected　to　600　°C　cyclic　high　temperature　(CHT)　shows　the　greatest　sensitivity　to　σ2.　Moreover,　CHT　and　σ2　have　a　significant　impact　on　the　rock　energy　release　efficiency.　This　study　documents　the　breakage　of　rock　bridges　by　thermally　induced　macrocracks　at　the　flaw　tips,　which　link　with　the　pre-existing　flaws　to　collectively　dominate　the　cracking　paths　and　failure　mechanisms.　Additionally,　increased　σ2　enhances　shear　mechanisms　under　room　temperature　(RT)　and　CHT400　°C　conditions,　while　it　diminishes　shear　mechanisms　under　CHT600　°C　conditions.　©　2025