Artificial　fractures　on　the　tunnel　face　can　promote　tunnel　boring　machine　(TBM)　performance　in　the　intact　rock　mass　with　high　rock　strength.　High-pressure　water　jet　(HPWJ)　is　a　feasible　choice　to　pre-cut　the　kerfs　on　the　tunnel　face　to　assist　in　TBM　tunnelling.　To　study　the　effects　of　different　layouts　of　the　TBM　cutter　and　HPWJ　on　the　cutting　performance　and　the　corresponding　rock　breakage　mechanism,　a　series　of　full-scale　linear　rock　cutting　tests　were　conducted.　The　analysis　included　the　TBM　cutter　force,　cutter　vibration,　rock　muck　and　rock-breaking　specific　energy.　According　to　the　results,　two　HPWJ-assisted　cutting　layouts　are　recommended.　One　is　arranging　the　HPWJ　nozzle　ahead　of　the　cutter,　making　the　cutter　cut　along　the　kerf.　The　rock　damage　zone　after　the　cutter　penetration　was　rather　limited　since　the　kerf　beneath　the　cutter　prevented　the　formation　of　the　pressurized　crushed　zone　and　the　generation　of　the　lateral　cracks　that　occurred　in　the　intact　rock.　The　lowest　cutter　force　and　vibration　were　obtained　with　the　shallow　kerf　depth　compared　with　the　other　layouts.　Creating　kerfs　with　a　depth　slightly　lower　than　the　cutter　penetration　is　suggested　to　vastly　save　energy.　Another　recommended　layout　is　arranging　the　nozzles　between　all　the　cutter　trajectories,　making　the　cutter　cut　along　the　middle　line　of　two　kerfs.　The　breakage　mechanism　turned　to　the　interaction　between　the　cutter　and　adjacent　kerfs,　macro-cracks　generated　from　the　cutter　tip　could　propagate　to　the　bottom　of　kerfs　on　both　sides.　The　cutter　force　and　the　magnitude　of　oscillations　decreased　with　the　increasing　kerf　depth.　The　largest　rock-breaking　volume　and　lowest　specific　energy　were　obtained　among　all　the　tests.　The　suggested　kerf　depth　is　about　twice　the　cutter　penetration,　above　which　the　specific　energy　would　not　significantly　decrease.　The　study　is　helpful　to　the　cutterhead　design　of　the　TBM　assisted　with　HPWJ　and　the　promotion　of　TBM　performance.　Linear　cutting　tests　using　the　HPWJ　and　full　scale　TBM　cutter　were　successively　performed　with　various　layouts.The　analysis　of　cutter　performance　comprises　force,　induced　vibration,　specific　energy　and　mucks　characteristics,　validating　the　feasibility　of　the　assistance　of　HPWJ.Arranging　HPWJ　nozzles　on　and　between　the　cutter　trajectories　were　recommended　to　drastically　reduce　the　cutter　force　and　specific　energy,　respectively