To　conduct　a　precise　assessment　of　elderly　passengers＇　accessibility　to　healthcare　services　via　bus,　this　study　constructs　bus　travel　chains　based　on　travel　data　from　elderly　cards,　infers　healthcare　activities　from　bus　travel　chains,　and　determines　the　actual　travel　demands　and　durations.　Real-time　bus　arrival　data　is　introduced　to　reflect　the　impact　of　the　actual　bus　operation　level　on　the　healthcare　accessibility.　To　reflect　the　entire　travel　process,　a　real　travel　cost　matrix　including　waiting,　travel,　and　transfer　times　is　constructed.　Considering　the　difference　in　the　service　supply　capacity　of　different　hospitals,　the　comprehensive　service　capacity　index　is　constructed.　Hierarchical　service　radius　and　the　Gaussian　distance　decay　function　are　introduced,　and　the　calculation　method　of　accessibility　to　healthcare　services　by　bus　based　on　the　improved　two-step　floating　catchment　area　method　is　further　proposed.　Taking　the　area　within　Beijing＇s　Six　Ring　Road　as　a　case　study,　the　results　show　a　diminishing　trend　in　healthcare　service　accessibility　for　the　elderly,　gradually　decreasing　from　the　city　center　towards　peripheral　areas.　The　distribution　of　accessibility　in　the　peripheral　areas　also　shows　spatial　heterogeneity,　in　which　the　eastern　and　western　areas　beyond　the　Fifth　Ring　Road　exhibit　relatively　favorable　accessibility,　while　the　northern　and　southeastern　zones　exhibit　comparatively　poorer　accessibility.　The　mean　accessibility　during　peak　hours　is　significantly　lower　than　that　during　off-peak　hours　in　all　regions.　This　study　provides　insights　for　improving　the　accessibility　of　elderly　to　healthcare　services　and　the　level　of　aging　adaptation　of　bus　system.　©　2024　Science　Press.　All　rights　reserved.