In　order　to　improve　the　seismic　and　energy　dissipation　capacity　of　the　whole　structure,　a　friction-oval　section　mild　steel　rod　composite　damper　(FOSRCD)　was　proposed,　and　its　working　principle　was　clarified.　The　finite　element　analysis　of　FOSRCD　was　carried　out,　and　the　effects　of　friction,　frequency　and　displacement　on　the　damper　performance　were　studied.　Considering　the　structural　characteristics　of　FOSRCD　and　the　mechanical　models　of　friction　dampers　and　mild　steel　rod　dampers,　the　restoring　force　model　of　the　composite　dampers　was　proposed　and　compared　with　the　numerical　simulation　results.　The　results　showed　that　the　FOSRCDs　had　good　performance　and　could　provide　stable　energy　dissipation　capacities　in　both　directions,　with　the　energy　dissipation　coefficient　exceeding　2.3　and　the　equivalent　damping　ratio　exceeding　0.37.　The　theoretical　analysis　results　were　in　good　agreement　with　the　numerical　simulation　results,　which　verified　the　theoretical　restoring　force　model;　the　FOSRCDs　make　full　use　of　the　friction　energy　dissipation　and　the　shear　and　bending　energy　dissipations　of　the　mild　steel　rod.　It　enables　the　two　dampers　to　work　together　to　achieve　the　purpose　of　multi-stage　energy　dissipation.　FOSRCD’s　structure　allows　it　to　dissipate　energy　in　both　the　X-　and　Y-directions.　The　composite　dampers　have　a　variety　of　restoring　force　models　and　can　be　utilized　in　a　wide　range　of　practical　applications.　©　2023　by　the　authors.