This　paper　uses　ABAQUS　software　to　perform　finite　element　simulation　on　eccentric　compression　member　of　corroded　circular　steel　tubes　strengthened　by　FRP　tube　grouting.　The　working　mechanisms,　failure　mode　and　the　lifting　of　mechanical　properties　are　investigated.　The　results　show　that　the　load–displacement　curve　of　the　member　represents　both　bilinear　and　trilinear　models.　The　former　is　in　the　overall　buckling　failure　mode,　while　the　latter　is　in　the　strength　failure　mode　of　the　circular　steel　tube　with　bare　ends.　After　strengthening,　the　bearing　capacity　increases　by　up　to　114.99%.　Moreover,　the　increase　positively　correlates　with　corrosion　rate,　grouting　thickness,　and　FRP　tube　thickness.　It　first　decreases　before　increasing　as　the　slenderness　ratio　changes,　while　the　concrete　strength　has　little　effect.　At　the　same　time,　the　bound　flexural　stiffness　ratio　is　derived　and　provides　reference　suggestions　for　the　practical　engineering　application　of　FRP　tube　grouting　to　strengthen　corroded　steel　structures.　©　2023　Institution　of　Structural　Engineers