Abstract: In order to obtain the regulation of particle motion in solid rocket motor(SRM) under overload conditions, theoretical and numerical methods are used to analyze particle motion and concentration under different acceleration. A three-dimensional model of viscous compressible two-phase flow in the SRM was established. The Eulerian-Lagrangian multiphase model was used to calculate the trajectories of the discrete phase. This analysis used the numerical solution of Reynolds-averaged Navier-Stokes equations for the continuous phase, coupled with a Lagrangian analysis for the discrete phase to simulate the two-phase internal flow. Results show that the lateral overload increases particle residence time in the SRM by changing the trajectory of particles. In addition, the surface of the SRM combustion chamber and the nozzle convergent section both have an area with high particle concentration, which has an multimodal distribution. Furthermore, different lateral and axial overload leads to the change of particle concentration in surface of the SRM combustion chamber and the nozzle convergent section, which is caused by transforming the direction of particle.