Abstract: Thermal processing characteristics are the key factors determining the intrinsic quality of cut tobacco during the conditioning process, mainly including material moisture content and temperature. Due to the enclosed space of the conditioner, it is difficult to accurately characterize the variation laws of moisture content and temperature of cut tobacco inside the drum under the influence of hot air and mixed water. In this study, a digital characterization method for the thermal processing characteristics of cut tobacco during the conditioning process, which is suitable for actual production, is proposed. Firstly, a full-scale conditioner drum model and a cut tobacco model are constructed. Then, online production data are collected, and the variation laws of sensitive process parameters (such as atomized water flow rate and direct-injection steam flow rate) and equipment operation parameters (such as the rotational speed of the conditioner drum) are extracted as the boundary conditions of the numerical model. Combined with the computational fluid dynamics-discrete element method (CFD-DEM) coupling theory, a multi-field coupling numerical model of flexible cut tobacco discrete-phase particles, drum, and flow field is established to analyze the thermal processing characteristics and transfer laws of cut tobacco during conditioning under different operating conditions. The results show that: ① The temperature inside the conditioner drum increases continuously with time and tends to stabilize at 40 seconds; the high-temperature region gradually spreads backward in the axial direction, and there is a large temperature difference between the feed chamber and the discharge chamber in the radial direction, with the temperature in the upper part being higher than that in the lower part; ② The moisture content of cut tobacco inside the drum first increases and then decreases with the rise of temperature, while the temperature of cut tobacco rises continuously and then stabilizes, followed by a decrease at the discharge chamber; ③ The errors between the simulation results (including temperature inside the drum, moisture content of cut tobacco at the outlet, outlet temperature, and simulation time) and the comparative test results are within a reasonable range, indicating that this simulation study has guiding significance for realizing the visualization inside the loosening and conditioning drum.