Due　to　the　extreme　water　sensitivity　of　shale,　the　excavation　of　shale　underground　engineering　is　prone　to　major　disaster　accidents　such　as　roof　falls　and　collapses.　However,　current　investigations　have　failed　to　fully　explain　the　mechanisms　by　which　water　content　affects　shale　damage　behaviors.　In　this　study,　the　acousto-mechanical　properties　and　failure　behaviors　of　laminated　shale　under　different　confining　pressures　σ3　are　investigated　with　the　aid　of　AE　monitoring　for　three　different　water　content　states.　The　results　show　that　the　shale　strength　decreases　with　the　increase　of　the　water　content,　but　it　increases　as　the　confining　pressure　σ3　increases.　For　the　shale,　the　change　in　the　wetting　angle　and　the　distance　between　the　centroids　of　the　two　adjacent　particles　inside　the　bedding　plane　is　more　prominent　than　the　surrounding　shale　matrix,　and　the　swelling　pressure　is　generated　among　the　clay　minerals,　which　are　the　two　main　mechanisms　for　the　bedding-participating　failure　and　the　shale　softening　after　immersion.　Moreover,　with　the　increase　of　the　water　content　and　σ3,　the　damage　mode　of　shale　specimens　gradually　changes　from　tension　damage　to　shear　damage.　Controlled　by　bedding,　shale　failure　shows　significant　suddenness　without　clear　acoustical　precursors.　This　study　provides　experimental　and　theoretical　bases　for　the　stability　analysis　of　shale　underground　engineering.　©　2023　by　the　authors.