In-situ　stress　is　a　significant　factor　influencing　TBM　tunneling　for　deep　tunnels,　especially　for　the　construction　of　deep　repository　for　radioactive　waste　disposal.　Beishan　area　of　Gansu　Province　is　the　first　preferred　area　for　high-level　radioactive　waste　disposal　repository　in　China,　and　the　feasibility　of　using　TBM　technology　in　Beishan　area　is　investigated　in　recent　years.　In　this　paper,　six　levels　of　in-situ　stress　related　to　different　depths　from　ground　to　500m　at　Beishan　area　were　selected　and　the　influence　of　in-situ　stress　on　rock　fragmentation　was　investigated　by　linear　cutting　test.　The　rock　samples　were　collected　from　the　Jijicao　site　in　Beishan　area,　with　uniaxial　compressive　strength　of　105.6MPa.　The　test　results　show　that:　1)　there　is　a　clear　power　function　correlation　between　the　penetration　and　the　normal　cutter　force　for　each　stressed　condition,　and　the　higher　the　confining　stress,　the　smaller　the　gradient　of　the　power　function　curve,　which　means　slower　increase　of　penetration　rate　under　the　same　cutterhead　thrust;　2)　the　required　normal　cutter　force　increases　with　the　increase　of　overburden　as　the　corresponding　in-situ　stress　increases.　Based　on　the　laboratory　testing,　the　Specific　Rock　Mass　Boreability　Index　model　was　modified　and　further　used　in　the　prediction　of　TBM　performance　at　different　depths　on　Jijicao　site.　This　paper　helps　better　understanding　of　rock　fragmentation　mechanism　in　TBM　tunneling　in　stressed　ground,　and　also　provides　reference　on　parameter　selection　for　TBM　operation　in　deep　tunnel　tunnelling.　©　Published　under　licence　by　IOP　Publishing　Ltd.