To　investigate　the　mechanical　behaviour　and　failure　mechanism　of　flawed　rock　masses　under　biaxial　stress　conditions,　a　series　of　biaxial　compression　experiments　are　conducted　on　red　sandstone　specimens　containing　combined　flaws　of　the　circular　hole　and　perforated　symmetric　fissure　combined　with　acoustic　emission　(AE)　technology　in　this　work.　The　results　show　a　close　association　between　the　stress–strain　curve　morphology　and　confining　stress,　both　the　biaxial　compression　strength　and　elastic　modulus　exhibit　an　upward　trend　with　increasing　fissure　angle　and　confining　stress.　The　maximum　AE　energy　and　cumulative　AE　energy　both　increase　with　higher　confining　stress.　The　crack　types　in　the　specimens　are　identified　by　analyzing　the　average　frequency/rise　time/amplitude　value　distribution,　revealing　a　gradual　decrease　in　the　percentage　of　tensile　cracks　with　increasing　fissure　angle.　An　AE　localization　algorithm　based　on　the　least　absolute　value　method　is　applied　to　pinpoint　AE　events　during　biaxial　compression,　and　AE　events　distribution　is　analyzed　through　the　kernel　density　estimation.　The　crack　extension　behaviour　is　described　based　on　the　movement　of　the　maximum　kernel　density　points,　which　initially　exhibits　a　progression　from　both　ends　of　the　specimen　toward　the　central　region　and　subsequently　from　the　central　fissure　tip　toward　the　two　ends.　©　2025　The　Author(s).