To　solve　the　problem　of　precision　of　the　current　elastic-plastic　models　in　masonry　structures　and　the　need　for　seismic　fragility　analysis,　the　equivalent　diagonal　brace　model　was　introduced　into　the　finite　element　model　of　masonry　structures.　According　to　the　lateral　stiffness　characteristics　of　solid　wall,　window　wall,　and　door　wall,　the　corresponding　equivalent　diagonal　brace　width　calculation　formula　was　proposed.　Based　on　the　equivalent　diagonal　brace　model,　the　elastic-plastic　finite　element　models　of　the　three　types　of　masonry　walls　were　established　and　analyzed　under　low-cycle　reciprocating　loading.　The　accuracy　and　practicability　of　the　models　were　verified　by　the　test　results.　On　this　basis,　a　typical　three-story　masonry　structure　finite　element　model　was　established.　Following　the　incremental　dynamic　analysis　method,　seismic　fragility　analysis　was　carried　out　by　taking　the　maximum　inter-story　displacement　angle　and　elastic-plastic　energy　dissipation　difference　as　damage　parameters.　The　fragility　curves　of　the　masonry　structure　model　of　transverse　wall　and　that　of　both　longitudinal　and　transverse　walls　were　compared　and　analyzed.　Results　show　that　the　traditional　inter-story　displacement　angle　could　not　fully　represent　the　seismic　performance　of　the　longitudinal　wall,　and　the　damage　parameters　based　on　energy　could　more　accurately　reflect　the　evolution　process　of　structural　damage　and　the　performance　of　the　longitudinal　wall.　The　finite　element　model　of　masonry　structures　with　appropriate　precision　should　be　established　according　to　the　needs　of　fragility　evaluation　and　calculation　efficiency.　Copyright　©2020　Journal　of　Harbin　Institute　of　Technology.All　rights　reserved.