<p>Ensuring the safety of the mixing process materials of cast explosives is a fundamental requirement of the production process. The sensitivity of the process materials during the mixing process is influenced by factors such as container wall heating, frictional heat generation, surface roughness of the container wall, and material composition. There is an urgent need to establish safety thresholds for the process materials, considering the component content, container wall roughness, and temperature–friction coupling effects. To address these issues, this paper proposes a standardized thermal–friction coupling sensitivity testing method for cast explosive mixing process materials. Samples of the process materials were tested, and the effects of component content, container wall roughness, temperature and frictional excitation on material sensitivity were analyzed, determining the safety thresholds for the process materials. The results indicate that the friction sensibility of RDX, RDX/Al powder, RDX/Al powder/AP, and mixed slurry increases with increasing temperature. Under constant conditions, an increase in the roughness of the porcelain plate and rod also leads to a rise in friction sensitivity. The addition of aluminum powder significantly reduces the friction sensitivity of RDX/Al powder mixtures, and the sensitivity decreases considerably as the aluminum powder content increases. The friction sensitivity of RDX/AP mixtures is influenced by both the RDX/AP ratio and temperature. The sensitivity decreases with increasing temperature, and a turning point appears as the AP content changes. These findings offer scientific evidence to support the safety assessment of the mixing process materials and the optimization of the mixing process parameters.</p>