Mountain　dynamic　response　monitoring　plays　important　roles　in　geological　disaster　evolution　monitoring　and　warning.　A　distributed　mountain　seismic　monitoring　and　steady-state　analysis　method　is　demonstrated　with　distributed　acoustic　sensing　(DAS)　and　a　natural　earthquake　stimulus.　In　the　field　test,　the　seismic　detection　capability　is　first　verified　by　comparing　the　recorded　seismic　waveforms　from　DAS　and　existing　seismic　stations.　The　vibration　signal　difference　between　steady-state　and　unsteady-state　mountain　parts　is　apparent;　the　operational　modal　analysis　method　is　utilized　to　extract　the　response　difference　and　to　monitor　the　disaster　evolution　process.　The　proposed　method　has　many　advantages,　including　being　easy　to　deploy,　all-weather　online　monitoring,　etc.　It　is　believed　that　the　proposed　method　will　broaden　the　DAS　application　scope　and　promote　the　development　of　geological　disaster　early　warning　such　as　landslides　and　collapses.　(c)　2023　Optica　Publishing　Group