Layered　transition　metal　dichalcogenides　(TMDs)　are　a　promising　platform　for　new　photonic　and　optoelectronic　devices.　Exciton-phonon　interaction　is　critical　in　determining　their　characteristics　such　as　the　exciton　coherence　lifetime　and　linewidth.　However,　the　exciton　linewidth　obtained　by　conventional　reflection　spectrum　is　greatly　affected　by　the　background　signals,　and　the　research　into　exciton-phonon　coupling　difference　induced　by　stacking-order　in　multi-layer　structures　is　still　lacking.　In　this　work,　the　temperature-dependent　exciton　linewidths　of　CVD-grown　large-area　monolayer,　2H　and　3R-stacking　bilayer　WS2　based　on　a　self-designed　reflective　magnetic　circular　dichroism　(MCD)　spectrum　are　systematically　investigated.　It　is　found　that　2H-bilayer　WS2　exhibits　significantly　larger　exciton　linewidth　compared　with　monolayer　and　3R　bilayer,　which　can　be　attributed　to　the　appearance　of　new　phonon-assisted　relaxation　channels　caused　by　interlayer　coupling.　Meanwhile,　3R　bilayer　with　a　redshifted　exciton　peak　has　a　narrower　linewidth　than　2H　phase　because　the　interlayer　hopping　is　suppressed,　resulting　in　the　absence　of　interlayer　scattering　channel.　These　results　provide　intuitive　evidence　for　the　exciton　linewidth-broadening　and　exciton-phonon　coupling　in　different　stacked　layers　and　open　up　new　vistas　for　the　development　of　TMD-based　narrow-linewidth　nano-sensors　devices.