A　three-dimensional　(3D)　mesoscale　model　was　established　in　the　present　work　with　considering　the　heterogeneity　of　concrete　materials　and　the　surface　characteristics　of　deformed　steel　bars.　In　the　simulation,　the　interaction　between　deformed　rebar　and　concrete　is　taken　into　account,　including　mechanical　interlocking　and　frictional　resistance.　The　sequentially　coupled　thermal-stress　analysis　procedure　was　employed　to　model　the　process　of　pull-out　of　deformed　steel　bar　after　cooling　from　high　temperature.　Comparison　with　the　results　of　the　pull-out　test　illustrates　the　correctness　of　the　mesoscale　simulation　results.　Then,　the　influence　of　aggregate　types　and　elevated　temperatures　on　the　bond　properties　were　discussed.　Considering　the　simulation　results,　a　calculation　formula　for　the　bond　stress-slip　curve　after　cooling　from　high　temperature　was　proposed　based　on　the　recommendations　in　the　existing　codes　for　the　cases　of　room　temperature.　The　results　show　that　the　reduction　of　peak　bond　strength　is　directly　bound　up　with　the　heat　transfer　and　mechanical　performance　of　the　aggregates.　When　the　deformed　rebar　is　pulled　out　under　the　displacement　load,　the　development　process　of　concrete　cracks　with　different　aggregates　is　obviously　different.　Comparing　the　results　obtained　by　the　calculation　formula　proposed　in　the　present　work　with　the　numerical　simulation　results,　one　can　notice　the　good　consistency　between　them,　which　means　the　effectiveness　of　the　proposed　formula.