In　recent　years,　the　application　of　textile　reinforced　mortar　(TRM)　as　an　overlay　has　become　an　important　method　for　repairing　and　strengthening　old　masonry　structures.　However,　the　quantitative　analysis　and　design　of　TRM-strengthened　reinforced　concrete　(RC)　beams　are　still　limited.　To　address　this　gap,　a　nonlinear　finite　element　(FE)　model　is　proposed　in　this　study　to　simulate　the　flexural　behavior　of　TRM-strengthened　RC　beams.　The　developed　model　is　validated　using　experimental　results　and　subsequently　utilized　for　the　design　of　TRMstrengthened　RC　beams.　Various　TRM　design　parameters,　including　the　number　of　textile　layers,　textile　longitudinal　length,　and　textile　mesh　size,　are　parametrically　investigated.　The　modelling　results　reveal　that　increasing　the　number　of　textile　layers　and　longitudinal　length　while　decreasing　the　textile　mesh　size　can　enhance　the　bending　strength　of　TRM-strengthened　RC　beams.　Furthermore,　an　analytical　model　is　proposed　to　predict　the　flexural　strength　of　TRM-strengthened　RC　beams,　facilitating　rapid　strength　estimation　of　TRMstrengthened　RC　beams.　The　predicted　results　demonstrate　good　agreement　with　the　numerical　simulation　results.　The　established　FE　models　can　predict　the　bending　performance　of　TRM-strengthened　RC　beams　under　different　reinforcement　conditions,　and　the　simulation　outcomes　can　provide　valuable　guidance　for　their　design.