Calendering is a critical process in the production of double-base propellants. In practical production, grooved calenders are typically used to achieve material plasticization, dehydration, and granulation, thereby enhancing the material densificatio and mechanical properties. The surface roughness of the calender rolls is the core factor controlling the adhesion of the propellant material to the rolls. This alters the extrusion, friction, and shearing forces acting on the propellant material, ultimately affecting the quality and safety of the calendering process. To investigate the wall slip characteristics during this process, this study established a dynamic model of the propellant calendering process based on non-Newtonian fluid mechanics. The governing equations were solved using the finite element method and Polyflow software. On this basis, the influence law of the wall slip coefficient on the force and motion of the propellant material was analyzed. The simulation results indicate that the wall slip coefficient affects the pressure and outlet velocity distribution of the propellant material during the calendering process, with pressure variations being more significant A larger wall slip coefficient at the contact area between the calender rolls and the propellant material leads to a greater the maximum pressure and outlet velocity, as well as more drastic change in the normal pressure between the rolls. Therefore, a reasonable selection of the surface roughness of the calender rolls can enhance material adhesion while ensuring production safety. The research provides a theoretical basis for choosing surface roughness of the calender rolls in the calendering process of double-base propellants.