The　bond　properties　of　corroded　reinforcing　bars　in　concrete　are　mainly　determined　by　the　failure　time　and　ultimate　capacity　of　reinforced　concrete　(RC)　structures.　In　this　study,　98　cube　specimens　were　used　to　study　the　corrosion　effect　on　the　bond　failure　mechanism　of　RC　structures　under　transient　high　temperature.　Firstly,　an　electrification　accelerated　corrosion　test　was　carried　out　to　fabricate　the　corroded　specimen　with　various　corrosion　degrees　(0　%,　5　%,　10　%,　and　15　%).　Secondly,　the　undamaged　specimen　was　conducted　by　pull-out　test　at　ambient　temperature　to　obtain　the　initial　bond　strength,　and　then　a　transient　temperature　test　under　sustained　load　was　also　performed　to　analyze　the　effects　of　different　load　ratios,　concrete　strength,　and　corrosion　degrees　on　the　bond　behavior.　SEM　(Scanning　Electron　Microscope)　was　conducted　to　verify　the　damage　level　by　comparing　the　interfacial　transition　zone.　Test　results　indicate　that　the　coupling　effect　of　corrosion,　fatigue　load,　and　high　temperature　increases　the　carbonization　level　of　the　specimens　and　reduces　the　concrete　compressive　strength　after　bonding　damage.　The　ultrasonic　pulse　velocity　decreases　with　increasing　corrosion　degree　and　sustained　load　level　and　decreases　with　increasing　concrete　strength　grade.　Under　the　coupling　effect　of　corrosion,　high　temperature,　and　sustained　load,　the　bonding　failure　time　is　significantly　affected　by　the　sustained　load　ratio,　and　the　failure　slip　is　determined　by　corrosion　and　temperature.　Finally,　an　empirical　slip-location　constitutive　model　was　proposed,　incorporating　the　sustained　load　ratio,　corrosion　degree,　and　temperature.　The　accuracy　of　the　predicted　model　agrees　with　the　error　requirement,　and　the　constitutive　model　provides　a　theoretical　basis　for　the　collapse　warning　of　corroded　structures　under　fire.