Understanding　the　deformation　failure　behavior　of　the　composite　rock　strata　has　important　implications　for　deep　underground　engineering　construction.　Based　on　the　uniaxial　compression　laboratory　test　of　the　specimens　of　composite　rock　strata　containing　holes,　the　microscopic　parameters　in　the　particle　discrete　element　simulation　are　firstly　calibrated.　Then,　the　mechanical　properties　and　failure　characteristics　of　the　composite　rock　strata　with　holes　under　different　confining　pressures　are　studied.　The　results　show　that　different　dip　angles　and　confining　pressures　have　significant　effects　on　the　peak　strength　and　elastic　modulus　of　the　specimens.　Under　the　same　confining　pressure,　the　peak　strength　and　elastic　modulus　decrease　first　and　then　increase　with　the　increasing　dip　angle.　As　the　dip　angle　is　constant,　both　the　peak　strength　and　elastic　modulus　gradually　increase　with　the　increase　in　confining　pressure.　It　shows　that　the　first　area　to　be　damaged　in　composite　rock　strata　transfers　from　soft　rock　to　hard　rock　with　the　increase　in　dip　angle.　With　the　increase　in　confining　pressure,　the　range　of　tensile　stress　concentration　area　decreases　substantially,　while　the　range　of　compressive　stress　concentration　area　changes　less.