Understanding　the　effects　of　thermal　fatigue　damage　on　the　failure　mechanisms　of　rocks　is　a　key　concern　in　underground　engineering.　The　effects　of　high　temperature　on　the　physical–mechanical　behaviors　and　the　failure　mechanism　of　basalt　under　uniaxial　compression　are　investigated　with　a　combination　of　acoustic　emission　(AE),　computed　tomography　(CT),　and　scanning　electron　microscope　(SEM).　The　high　temperature　heavily　affects　the　physical–mechanical　properties　of　basalt　but　has　no　effect　on　the　mineral　compositions.　The　evolution　characteristics　of　inter-event　time　function　F(τ)　and　cumulative　AE　energy　can　be　employed　to　characterize　the　fracture　process　of　thermally　damaged　basalt.　The　damage　mechanisms　of　thermal　fatigue　are　attributed　to　the　occurrence　of　intergranular　cracks,　intragranular　cracks,　and　transgranular　cracks　and　irregular　holes　within　basalt.　The　failure　mechanisms　of　basalt　change　from　shear　fracture　to　mixed　tensile–shear　fracture　and　finally　to　tensile　fracture　based　on　the　statistical　characteristics　of　low　and　high　dominant　frequencies.　©　2023　John　Wiley　&　Sons　Ltd.