To　study　the　seismic　restoring　force　model　of　basalt　fiber　reinforced　polymer　(BFRP)　shell　reinforced　RC　pier　columns　without　drainage,　numerical　analysis　was　conducted　on　the　shell　reinforced　reinforced　concrete　(RC)　pier　columns　using　OpenSees　finite　element　software　on　the　basis　of　quasi-static　tests.　The　main　research　parameters　were　the　strength　of　filled　layer　concrete,　shell　thickness,　reinforcement　height,　and　axial　compression　ratio.　Results　show　that　the　higher　the　strength　level　of　the　filled　layer　concrete,　the　stronger　the　seismic　performance　of　the　pier　column.　However,　the　seismic　performance　of　the　filled　layer　concrete　with　a　strength　level　above　C40　is　relatively　similar　to　that　of　the　pier　columns.　The　seismic　performance　of　pier　columns　with　larger　thickness　reinforced　by　formwork　is　better　than　that　of　pier　columns　with　smaller　thickness.　When　the　reinforcement　height　of　the　formwork　is　high,　the　seismic　performance　of　the　pier　column　is　good.　When　the　reinforcement　height　is　greater　than　2-3　times　the　plastic　hinge　height　of　the　original　pier　columns,　the　seismic　performance　improvement　effect　tends　to　be　stable.　The　larger　the　axial　compression　ratio,　the　faster　the　stiffness　degradation　of　the　pier　column,　which　is　unfavorable　for　the　development　of　ductility.　Then　through　data　regression　analysis,　a　restoring　force　model　for　BFRP　shell　reinforced　RC　pier　columns　was　established.　The　comparison　shows　that　the　restoring　force　model　fitted　well　with　the　experimental　curve　and　could　effectively　reflect　the　hysteresis　performance　of　the　reinforced　pier　columns,　providing　reference　for　the　seismic　performance　analysis　of　such　structures.　©　2024　Chinese　Vibration　Engineering　Society.　All　rights　reserved.