Large-scale modular steel compartments contain wide internal spaces and substantial combustible fuel loads, promoting severe thermal exposure during real fires. Concrete-Filled Tube (CFT) columns are commonly used in these structures due to their high compressive capacity, yet their performance can deteriorate significantly under fire-induced heating. While realistic thermal boundary conditions are essential for evaluating their response, direct implementation of experimental temperature data into FEM-based heat-transfer analysis remains challenging. This study establishes a coupled simulation framework that integrates real-scale compartment fire data with numerical analysis by linking Fire Dynamics Simulator (FDS) outputs to ABAQUS thermal modelling. A full-scale modular fire test was conducted in accordance with KS F ISO 9705-1 to obtain authentic fire temperature development, and Adiabatic Surface Temperature (AST) was extracted using BNDF settings to formulate the thermal boundary conditions. The extracted thermal field was subsequently mapped to CFT column surfaces within ABAQUS, enabling heat-transfer analysis that accurately reflects experimentally observed exposure. Verification of the temperature-mapping process demonstrated strong agreement between BNDF-derived and ABAQUS-applied temperatures, confirming the reliability and fidelity of the coupled FDS–ABAQUS methodology for assessing the thermal response of CFT columns in modular compartment fires