To　improve　the　computational　efficiency　of　vibration　characteristics　and　reliability　analysis　for　a　detailed　numerical　model　of　the　mistuned　turbine　bladed　disk,　a　new　methodology　called　extremum　response　surface　method-based　improved　substructural　component　modal　synthesis　(ERSM-ISCMS)　is　proposed　by　combining　the　ISCMS　and　ERSM.　First,　the　degrees　of　freedom　of　the　detailed　finite　element　model　for　the　numerical　mistuned　turbine　bladed　disk　are　decreased　by　ISCMS,　which　is　called　as　reduced-order　model.　Compared　with　high　fidelity　finite　element　model,　the　time　saving　ratio　and　the　computational　accuracy　of　the　first　40　order　frequencies　are,　respectively,　36.37%　and　99.99%　similar　to　99.86%　obtained　by　ISCMS　under　the　same　working　environment,　which　can　satisfy　the　engineering　requirements.　Then,　the　ERSM　is　applied　to　analyze　the　dynamic　probability　of　the　maximum　vibration　response　for　the　numerical　mistuned　turbine　bladed　disk.　The　investigation　indicates　that　the　computational　efficiency　of　ERSM　is　higher　38.92%　than　that　of　traditional　RSM　in　the　same　computer　and　the　same　reduced-order　model.　Thus,　the　ERSM-ISCMS　is　a　more　effective　method　to　investigate　dynamic　probabilistic　analysis　of　the　mistuned　turbine　bladed　disk,　it　benefits　for　the　complex　structures　and　develops　the　theory　method　for　the　mechanical　reliability　design.　Published　by　Elsevier　Ltd.