In　this　paper,　a　thermo-mechanical　sequential　coupling　mesoscopic　simulation　method　was　established　and　verified,　which　considered　the　interaction　between　steel　tube　and　meso-components　of　concrete　due　to　the　difference　in　thermal　parameters,　as　well　as　the　low-temperature　effect　on　mechanical　parameters.　On　the　basis　of　heat　conduction　analysis,　the　damage　evolution　and　failure　mechanism　of　CFST　column　under　axial　compression　were　subsequently　revealed,　and　the　effects　of　low　temperature　(20,　−30,　−60　and　−80　°C),　cross-section　size　(160,　320,　480　and　640　mm),　width-thickness　ratio　(27,　36,　53　and　107)　and　cross-section　shape　(square　and　circular)　on　axial　compression　performance　and　the　corresponding　size　effect　of　CFST　columns　were　quantitatively　analysed.　Research　results　show　that　the　low-temperature　action　can　enhance　the　nominal　peak　strength　and　residual　strength　of　CFST　column,　but　weaken　the　ductility.　As　the　cross-section　size　increases　from　160　to　640　mm,　all　the　nominal　peak　strength,　nominal　residual　strength　and　peak　strain　of　circular　CFST　column　decrease　with　the　maximum　reductions　of　16.2,　28.7　and　16.9%,　respectively.　Besides,　the　low-temperature　action　can　enhance　the　size　effect　on　nominal　peak　strength　of　CFST　column　with　the　maximum　increase　of　68.8%.　Whether　at　ambient　or　low　temperature,　the　size　effect　on　nominal　peak　strength　of　square　column　is　stronger　than　that　of　circular　one.　The　size　effect　behaviour　on　axial　compressive　peak　strength　at　various　temperatures　can　be　also　well　described　by　the　previous　proposed　prediction　formula.　The　research　results　of　this　paper　can　provide　reference　for　the　engineering　application　of　large-sized　CFST　columns　in　the　extreme　low-temperature　environment.　©　2024　Elsevier　Ltd