In order to investigate the mechanical response process of porous propellant under impact loading and the effect of geometric parameter changes on the mechanical properties of the particles， ANSYS/LS-DYNA was used to establish the numerical models of seven-hole and nineteen-hole propellants to simulate the force of the particles under impact loading. Then， the models of single-hole propellant， seven-hole and nineteen-hole propellants with aspect ratios of 1∶1 and 2∶1， and lace-shaped seven-hole and nineteen-hole propellants were established to study the influence of the number of holes， aspect ratios and shape on propellant stress. The results show that the particles rebound after being compressed， the stress on the surface in contact with the drop hammer increased gradually from the center to the boundary， and the middle of the particles expanded. The increase of the number of holes will change the continuity of the stress distribution on the end surface due to the stress concentration at the hole. Compared with the single-hole propellant， the duration under stress and the maximum compressive displacement of the seven-hole propellant are increased by 3.39% and 3.76%， respectively， whereas the duration under stress and the maximum compressive displacement of the nineteen-hole propellant are increased by 10.17% and 15.05%， respectively. When the number of holes remains constant and the aspect ratio increases from 1∶1 to 2∶1， the peak stress decreases and the peak compressive displacement increases. The lace-shaped particles were more prone to cause stress concentration in the concave of lace than the cylindrical ones. The study of the stress response process of the propellant and its influencing factors provides fundamental data to study the mechanical properties of the propellant.