A　novel　methodology　is　established　for　the　reasonable　seismic　function　evaluation　of　urban　water　supply　network　from　the　perspectives　of　supplying　water　for　daily　living　and　firefighting.　First，based　on　the　seismic　fragility　model　of　pipelines　and　the　fire　risk　model　of　user　nodes，the　physical　seismic　damage　scenario　of　water　supply　network　is　generated　for　the　target　peak　ground　acceleration.　Next，the　hydraulic　model　is　modified　according　to　the　physical　seismic　damage　scenario　of　water　supply　network　while　the　hydraulic　adjustment　of　water　flow　in　the　water　supply　network　is　performed　based　on　the　pressure-dependent　demand　model.　Afterwards，the　function　of　water　supply　network　for　post-earthquake　daily　living　and　firefighting　is　evaluated，and　the　influence　of　firefighting　water　demand　on　daily　living　water　demand　is　discussed.　Finally，　the　relationship　between　serviceability　indexes　and　reliability　indexes　at　different　peak　ground　acceleration　is　revealed.　The　numerical　results　show　that　at　the　same　peak　ground　acceleration，the　evaluation　values　based　on　serviceability　indexes　are　greater　than　those　based　on　reliability　indexes.　Under　the　action　of　small　peak　ground　acceleration（0.2　g　and　0.25　g），both　daily　living　and　firefighting　water　demand　can　be　met　at　the　same　time，and　firefighting　water　demand　has　little　effect　on　daily　living　water　demand.　Under　the　action　of　large　peak　ground　acceleration（0.40　g　and　0.45　g），due　to　the　serious　damage　of　the　water　supply　network，both　daily　living　and　firefighting　water　demand　can　not　be　well　satisfied，and　firefighting　water　demand　has　little　impact　on　daily　living　water　demand.　Under　the　action　of　medium　peak　ground　acceleration（0.30　g　and　0.35　g），firefighting　water　demand　has　a　great　influence　on　daily　living　water　demand，about　7　%.　©　2024　Science　Press.　All　rights　reserved.