In　response　to　the　need　for　tunnel　microseismic　(MS)　monitoring　and　to　avoid　problems　such　as　the　damage　of　the　primary　support　caused　by　drilling　and　installing　acceleration　sensors,　this　article　proposes　a　new　sensor　installation　method　and　manufactures　a　novel　right-angle　bracket　for　vibration　acceleration　sensor　installation.　This　study　examines　the　measurement　errors　caused　by　vibration　transmission　through　the　right-angle　bracket.　Modal　analysis　revealed　that　the　low-order　mode　of　the　right-angle　bracket　system　is　about　three　times　or　more　the　main　frequency　of　tunnel　microseism,　making　it　suitable　for　tunnel　microseismic　monitoring.　Combining　field　experimental　tests　and　numerical　simulation,　the　time　and　frequency　domain　responses　of　the　installation　bracket　under　impact　load　were　studied.　The　vibration　differences　captured　by　the　sensors　installed　in　different　locations　were　compared　and　the　reasons　for　the　vibration　monitoring　differences　were　analyzed.