During　TBM　tunneling　at　the　great　depth,　problems　such　as　high　in　situ　stress,　groundwater　inflow　and　fractured　rock　masses　are　main　reasons　of　the　geotechnical　risk　occurrence　in　TBM　tunneling.　Thus　it　is　necessary　to　modify　TBM　and　optimize　TBM　operation　parameters　for　improving　TBM　performance　when　encountering　these　adverse　geological　conditions.　In　china,　two　of　four　headrace　tunnels　in　Jinping　II　hydropower　station　project　are　constructed　by　two　tunnel　boring　machines.　The　headrace　tunnels　are　approximately　16.7　km　in　length　and　the　maximum　overburden　depth　is　up　to　2,525m.　In　this　paper,　the　rock　masses　along　the　headrace　tunnels　of　Jinping　II　hydropower　station　are　assessed,　and　then　are　classified　into　three　typical　excavation　sections　according　to　the　main　controlling　factors　of　TBM　excavation.　The　three　typical　excavation　sections　are　the　normal　excavation　section,　the　excavation　section　controlled　by　high　in　situ　stress　and　the　excavation　section　controlled　by　large　groundwater　inflow,　respectively.　In　order　to　overcome　the　adverse　geological　conditions　in　these　typical　exaction　sections,　the　corresponding　modifications　and　operation　optimization　for　TBM　are　proposed　in　this　paper.　The　experiences　obtained　from　Jinping　II　hydropower　station　can　provide　useful　reference　and　guidance　for　TBM　tunneling　at　depth.　©　2013　Taylor　&　Francis　Group.