Calendering process is an important link in the production of propellants, where the morphology of the material becomes dense from loose under the action of thermal coupling, and its processing quality will directly affect the performance of propellants. At present, there are two major difficulties on the calendering process of propellant, namely, the lack of quantitative assessment of the calendering quality of propellant and the difficulty in determining the end point of the calendering process. In addition, due to the special characteristics of propellant calendering, it is difficult to monitor the movement and force of the material online, so numerical simulation has become an important tool to analyze and optimize the propellant calendering process. In this paper, for the calendering and plasticizing process of propellant, a dynamical model of propellant calendering process was established based on the Non-Newtonian hydrodynamic model, and the finite element method was used to solve the control equations with Polyflow software. The distributions of velocity, pressure, shear rate and viscosity of the material were obtained, and the effects of key process parameters such as roller gap and roller speed ratio on the calendering process were analyzed. Simulation results show that: the maximum pressure occurs in the upper position at the roller gap, and the maximum viscosity occurs in the grooves of the rollers; with the decreasing roller gap, the maximum pressure and shear rate on the calendering process increase and the pressure change is more significant; with the increasing of the roller speed ratio, the maximum shear rate of the material increases, but the increase of the maximum shear rate shows a decreasing trend. Therefore, under the premise of ensuring production safety, the calendering quality of propellant can be improved by appropriately reducing the roller gap and increasing the roller speed ratio within a certain range. The work in this paper can provide some theoretical guidance for the determination of calendering process parameters of propellant.