The　angular　displacement　of　the　beam-column　joints　of　the　frame　structure　is　small　under　earthquake　action,　and　the　seismic　mitigation　effect　of　ordinary　dampers　placed　at　the　joints　is　not　obvious.　The　displacement-amplified　torsional　damper　(DATD)　is　one　that　can　be　directly　installed　at　the　joint　and　has　a　displacement-amplifying　function.　Finite　element　numerical　simulation　on　the　mechanical　properties　of　DATD　was　carried　out　in　this　paper.　The　theoretical　mechanical　model　of　DATD　was　derived,　and　the　trilinear　mechanical　model　and　the　modified　Bouc-Wen　model　were　used　to　describe　the　mechanical　characteristics　of　DATD,　respectively.　Numerical　simulation　and　theoretical　analysis　results　agreed　well　with　the　experimental　results.　Then,　the　ETABS　software　was　adopted　to　analyze　and　compare　the　dynamic　responses　of　ordinary　frame　and　frame　equipped　with　DATAs　under　frequent　and　rare　earthquakes.　Results　showed　that　compared　with　the　uncontrolled　structure,　the　inter-story　angular　displacement,　top-story　displacement　and　internal　force　at　the　frame　joints　of　the　controlled　structure　equipped　with　DATDs　remarkably　decrease,　and　the　effect　of　energy　dissipating　and　vibration　control　is　obvious.　DATD　significantly　delays　the　structural　damage　at　the　joints　while　dissipating　the　input　earthquake　energy　and　reducing　the　structure＇s　dynamic　responses.　©　2022　Institution　of　Structural　Engineers