The　existed　1D　(dimensional)　and　2D　seismic　analysis　methods　couldn＇t　met　the　seismic　research　requirements　of　large　and　complex　underground　pipe　trench　structure　(LCUP).　In　order　to　solve　the　problem　that　the　seismic　performance　analysis　of　LCUP　requires　high　3D　modeling　ability　and　calculation　equipment,　an　integrated　seismic　analysis　method　of　＂overall　structure　+　key　nodes＂　was　proposed　in　this　paper.　Firstly,　according　to　the　research　purpose,　the　seismic　analysis　strategy　of　LCUP　was　proposed,　and　the　main　factors　influencing　the　seismic　time　history　analysis　of　LCUP　were　analyzed　one　by　one,　and　a　series　of　accurate　analysis　parameters　and　simplified　assumptions　were　obtained.　Secondly,　the　3D　seismic　analysis　model　of　LCUP　was　established,　including　the　overall　pipe　trench　model　and　the　local　key　nodes　model,　and　the　material　parameters,　boundary　conditions,　ground　motion　and　calculation　conditions　of　the　model　were　determined.　Finally,　3D　seismic　time　history　analysis　was　carried　out　for　the　whole　structure　and　key　joints,　and　the　seismic　performance　evaluation　based　on　mechanics　and　deformation　was　carried　out.　The　seismic　performance　of　the　LCUP　met　the　design　requirements.　The　results　showed　that　the　method　didn＇t　only　meet　the　requirements　of　seismic　analysis　accuracy　and　depth　for　complex　underground　space　structure,　but　also　significantly　reduced　the　time　of　seismic　analysis　and　improves　the　research　efficiency.　This　research　method　will　provide　a　useful　reference　for　the　seismic　research　of　similar　large　complex　underground　structures.