Abstract: This paper establishes a thermo-chemo-mechanical coupling model to investigate the curing process of solid propellant, focusing on the distribution characteristics of temperature, curing degree, and surface stress at various stages, including the curing-heating, curing-holding, and cooling-ejection processes. The results show that during the curing stage, the internal temperature and curing degree of the propellant transform from a higher-outside-lower-inside to a higher-inside-lower-outside pattern. During the curing and cooling stages, the stress on the external surface increases nonlinearly. A higher curing holding temperature can significantly shorten the solidification time, but it also exacerbates the non-uniformity of curing degree within the propellant, leading to an increase in the maximum stress at each stage and the maximum deformation after ejection.