To　explore　the　effects　of　fiber　ratio,　cross-sectional　shape,　cross-sectional　size　and　axial　compression　ratio　on　the　torsional　performance　of　carbon　fiber　reinforced　polymer　(CFRP)-reinforced　concrete　(RC)　columns,　this　paper　employs　a　meso-scale　mechanical　analysis　method　that　can　simultaneously　consider　the　heterogeneity　of　concrete,　the　bond-slip　relationship　between　reinforcement　and　concrete,　and　the　interfacial　relationship　between　CFRP　sheets　and　concrete.　First,　a　three-dimensional　numerical　model　was　established　for　the　analysis　of　the　torsional　performance　of　CFRP　sheet-reinforced　RC　columns.　Subsequently,　the　numerical　simulation　results　based　on　this　model　were　compared　with　the　experimental　results　to　verify　the　rationality　of　the　loading　approach　and　the　method　of　externally　bonded　CFRP　sheets,　and　the　accuracy　of　material　parameters.　Finally,　based　on　the　meso-scale　mechanical　analysis　model,　the　influence　mechanism　of　the　fiber　ratio,　cross-sectional　shape,　cross-sectional　size　and　axial　compression　ratio　on　the　failure　modes　and　mechanical　properties　of　CFRP　sheet-reinforced　RC　columns　under　torsion　was　investigated.　Results　show　that　the　torsional　bearing　capacity　of　RC　columns　increases　with　the　increase　of　fiber　ratio,　but　the　improvement　rate　decreases　with　the　increase　of　fiber　ratio.　Influenced　by　the　distribution　of　confining　pressure,　the　effective　restraint　area　of　the　circular　section　is　larger　than　that　of　the　square　section,　making　the　restraint　effect　of　CFRP　sheet　on　the　circular　column　better　than　that　of　the　square　column.　The　size　effect　can　be　observed　in　the　nominal　torsional　strength　of　CFRP　sheet-reinforced　RC　columns.　The　torsional　bearing　capacity　firstly　increases　and　subsequently　decreases　with　the　increase　of　the　axial　compression　ratio,　and　reaches　its　maximum　capacity　at　n　=　0.　4.　Furthermore,　a　calculation　formula　for　the　torsional　bearing　capacity　of　FRP　sheet-reinforced　RC　members　is　proposed　by　superposing　specification　formulas.　Compared　with　the　numerical　simulation　results　in　this　paper,　the　formula　can　give　a　design　value　of　safety　redundancy　of　30.　2%,　which　can　be　initially　used　for　the　safety　design　of　torsional　bearing　capacity　of　CFRP　sheet-reinforced　RC　columns.　©　2024　Beijing　University　of　Technology.　All　rights　reserved.