Differential Thermal Analysis (DTA) was employed to investigate the energy evolution and thermal behavior of nitrocellulose (NC) during heating. As a primary energetic component in most propellants and explosives, NC contains thermally labile nitroester groups that readily decompose under thermal stimuli. Analyzing its thermal decomposition is critical for ensuring safety in NC production, transportation, storage, and application. Previous studies on milligram-scale NC thermal decomposition predominantly focused on experimental characterization. However, conventional DTA procedures involving multiple heating rates are time-consuming, necessitating integrated experimental and numerical approaches for rapid thermal analysis. This study conducted NC decomposition experiments at varied heating rates (2–10 K/min) using DTA, while developing a kinetic model describing milligram-scale NC decomposition processes. Governing equations were solved via the finite volume method, with chemical kinetic parameters (activation energy E and pre-exponential factor lnA) determined through the Kissinger method. Key findings include:All heating rate conditions exhibited a single exothermic peak, yielding E = 210.77 kJ/mol and lnA = 53.86 s⁻1.Increased heating rates produced steeper temperature differential curves, elevating both initial decomposition temperature (T_onset) and peak temperature (T_peak).Numerical simulations demonstrated ≤ 3.58% maximum deviation in T_onset and T_peak predictions across heating rates, validating model reliability. The proposed methodology provides an efficient tool for rapid assessment of thermal decomposition characteristics in milligram-scale energetic materials.