Microwave　irradiation　is　regarded　as　a　promising　technology　to　assist　mechanical　rock　breaking　for　its　substantial　advantages　in　reducing　cutter　wear　and　enhancing　rock　fracture.　Due　to　the　high　cost　of　laboratory　experiments　and　field　tests,　numerical　simulation　has　become　the　primary　method　to　investigate　key　issues　of　microwave-assisted　tunnel　boring　machine　(TBM)　cutting.　In　this　work,　an　electromagnetic-thermo-mechanical　coupled　approach　is　developed　to　implement　the　numerical　modelling　of　microwave-assisted　TBM　disc　cutting.　Different　numerical　methods　are　coupled　in　our　model　to　exert　their　respective　advantages,　including　the　electromagnetic-thermal　solution　of　COMSOL,　thermo-mechanical　fracture　simulation　of　the　lattice　spring　model　(LSM),　and　rock-cutter　contact　treatment　of　discontinuous　deformation　analysis　(DDA).　The　conversion　from　the　Euler　to　Lagrange　domain　is　adopted　to　address　the　motion　of　the　electromagnetic-thermal　field　in　the　disc　cutting　process.　The　proposed　coupled　numerical　approach　is　first　verified　by　the　corresponding　modelling　of　the　microwave-irradiated　rock　experiment,　in　which　the　coupled　approach　can　also　provide　the　evolution　process　of　three-dimensional　spatial　rock　fracturing　that　is　hard　to　obtain　in　the　experiment.　Implemented　into　the　numerical　full-scale　rock　linear　cutting　experiment,　our　coupled　approach　is　further　applied　to　simulate　rock　disc　cutting　assisted　by　microwave　irradiation.　Through　the　numerical　results,　it　is　concluded　that　a　moving　microwave　irradiation　is　better　for　reducing　the　cutter　normal　force　as　a　whole　in　the　disc　cutting　process.　For　the　moving　microwave　irradiation,　the　cutter　normal　force　will　decrease　with　the　increasing　microwave　power　or　decreasing　moving　speed,　in　which　the　microwave　power　plays　a　more　significant　role　when　the　total　microwave　energy　input　remains　the　same.　Finally,　the　curve　of　average　normal　force　reduction　with　the　microwave　energy　input　at　the　engineering　scale　is　analysed　based　on　the　numerical　results　of　our　coupled　model,　which　provides　some　insights　and　suggestions　for　the　future　practical　application　of　microwave-assisted　TBM　tunnelling.