Plasmon-free　surface-enhanced　Raman　spectroscopy　(SERS)　assisted　by　charge-transfer　(CT)　resonance　in　semiconductors　has　drawn　considerable　attention　in　the　past　decades　due　to　the　extraordinary　advantages　in　chemical　stability　and　homogeneity.　Unfortunately,　the　weak　confinement　of　excitation　light　in　semiconductor　nanostructures　and　2D　materials,　due　to　either　their　limited　refractive　indexes　or　atomic　thickness,　results　in　the　Raman　enhancement　by　nonmetallic　SERS　substrates　significantly　lower　than　the　noble　ones.　Here　a　novel　plasmon-free　SERS　probe　is　reported　by　a　tapered　optical　fiber　(TOF)　coated　with　monolayer-MoS2　(ML-MoS2),　where　the　TOF-supported　whispering-gallery　modes　(WGMs)　simultaneously　regulate　multiple-resonance　processes,　i.e.,　excitonic　resonance,　molecular　resonance,　charge-transfer　resonance　and　fluorescence　resonance　energy　transfer　processes,　in　the　ML-MoS2　and　analytes.　The　contribution　of　the　four　processes　promoted　by　WGM　to　enhancement　factor　of　Raman　intensity　(EFRI)　is　quantitatively　determined　by　four　dye　molecules　with　different　energy　levels.　The　Raman　enhancement　mechanism　of　WGM-promoted　multiple-resonances　is　therefore　revealed,　for　the　first　time.　The　maximum　EFRI　is　up　to　1.8　x　109　for　the　limit　of　detection　(LoD)　down　to　10-14　M.　The　ML-MoS2/TOF　SERS　probes　also　demonstrated　their　outstanding　feasibility　and　stability　facilitating　to　trace　detection　in　microdroplets　for　practical　applications　in　future.　A　plasmon-free　SERS　probe　by　a　tapered　optical　fiber　coated　with　monolayer-MoS2　is　demonstrated,　where　the　TOF-supported　whispering-gallery　modes　(WGMs)　simultaneously　regulate　excitonic,　molecular　and　charge-transfer　resonance　as　well　as　fluorescence　resonance　energy　transfer　processes　for　Raman　enhancement　with　1.8　x　109-fold　for　10-14　M.　The　SERS　probe　demonstrates　outstanding　feasibility　and　stability　facilitating　to　trace　detection　in　microdroplets　for　practical　applications.image