The　internal　circular　steel　tube　provides　considerable　confinement　to　the　core　concrete　in　a　Circular　Concrete-Filled　Double　Steel　Tubular　(CCFDST)　column　exposed　to　fire.　However,　no　constitutive　model　has　been　developed　for　the　core　concrete　at　elevated　temperatures　considering　confinement.　This　paper　develops　a　numerical　modeling　method　for　fire　resistance　of　CCFDST　columns　exposed　to　fire,　which　incorporates　a　confinement-dependent　model　for　concrete　at　elevated　temperatures.　The　confinement-dependent　model　is　implemented　through　a　MATLAB　algorithm.　The　algorithm　incorporates　several　segments:　an　average　temperature　model　is　proposed　to　address　the　temperature-gradient　problem　within　a　CCFDST　column;　the　temperature-dependent　failure　criterion　is　formulated　for　determining　the　compressive　strength　of　confined　concrete;　the　temperature-dependent　axial-to-lateral　strain　relation　is　established;　equations　are　derived　for　calculating　the　instantaneous　confining　stress　on　the　core　concrete　exerted　by　the　inner　steel　tube;　and　an　automatic　error-control　algorithm　is　designed　to　enforce　the　accuracy　of　the　proposed　stress-strain　model　for　the　core　concrete.　To　verify　the　proposed　model,　the　finite　element　model　developed　using　ABAQUS　is　presented,　which　incorporates　the　proposed　constitutive　model　for　the　core　concrete.　The　comparative　analysis　shows　that　the　developed　finite　element　model　predicts　well　with　the　existing　test　results.　This　suggests　that　the　proposed　model　is　reliable　and　can　be　implemented　in　numerical　models　for　the　fire　performance　simulations　of　CCFDST　columns.