In order to optimize the pressing parameters of polymer bonded explosive (PBX), the influence of bidirectional pressing process parameters on molding quality was analyzed. The bidirectional compaction process of PBX powder was numerically simulated by finite element method combined with Shima-Oyane and shear friction model, and the effects of different compaction pressures and holding temperatures on the relative density and equivalent stress of PBX powder were analyzed. The simulation results show that the compacting pressure has a greater influence on the forming density of the grain than holding temperature. At the same holding temperature, the relative density of the grain can be significantly increased and the relative density difference can be reduced by increasing the pressing pressure; at the same pressing pressure, the temperature has little effect on the relative density and the equivalent stress. When the upper and lower punches are pressed at the same speed, the edge density is 0.61 kg/m3 and the center density is 0.54 kg/m3 on the horizontal plane close to the upper and lower punches, and the edge density is 0.99 kg/m3 and the center density is 0.97 kg/m3 on the horizontal plane far away from the upper and lower punches.