Concrete-filled　steel　tubular　(CFST)　trusses　have　seen　recent　development　and　application　in　bridges　found　in　mountainous　regions　with　deep　valleys,　and　especially　in　seismic　zones.　In　this　study,　a　hybrid　CFST　truss　lightweight　bridge　was　selected　as　the　research　object.　This　bridge　is　composited　of　CFST　composite　truss　girders　(superstructure)　and　CFST　lattice　piers　(substructure).　Two　different　finite　element　models　(FEM)　for　nonlinear　seismic　response　analysis,　one　is　detailed　model　and　the　other　is　simplified　model,　were　established.　By　comparing　with　the　detailed　model,　the　results　of　the　shaking　table　test　as　well　as　the　real　bridge　test,　the　simplified　model　was　found　to　be　accurate.　Considering　the　CFST　columns＇　edge　strain,　the　most　unfavorable　input　direction　of　horizontal　ground　motion　was　perpendicular　to　the　connection　line　of　the　bearings　at　both　ends　of　the　main　girder.　Also,　the　simultaneous　influence　of　vertical　ground　motion　and　horizontal　ground　motion　needs　to　be　taken　into　consideration.　By　increasing　the　intensity　of　input　ground　motion,　the　yielding　order　of　CFST　lattice　piers　and　its　effect　on　the　seismic　response　were　also　discussed.　Results　indicated　that　the　bridge　was　in　the　elastic　stage　for　the　designed　seismic　ground　motion.　After　the　CFST　lattice　piers　reached　the　plastic　stage,　the　displacement　and　in-plane　bending　moment　had　larger　amplification　coefficients　compared　to　the　increase　coefficient　of　the　input　ground　motion,　while　had　a　much　smaller　axial　force　amplification　coefficient.　Moreover,　the　in-plane　bending　moment　had　a　larger　amplification　coefficient　in　high　piers　compared　to　short　piers.　Too　many　nodes　and　elements　in　the　detailed　model　of　the　hybrid　concrete-filled　steel　tubular　truss　lightweight　bridge　will　cause　low　computational　efficiency　and　difficulty　in　error　detecting　in　seismic　analysis.　Therefore,　a　simplified　fiber　beam-column　element　model　having　efficient　computation　and　ability　to　predict　the　seismic　response　of　structures　precisely　was　established　and　verified.　And　the　nonlinear　dynamic　response　of　this　new　type　of　lightweight　bridge　under　strong　earthquakes　was　investigated.　image