The work aims to employ numerical simulation methods to study the propagation and attenuation of explosive shock waves within gravel particle layers to investigate the wave-dissipation mechanism of gravel particulate media and its influential factors. A particle distribution algorithm was developed using Python and mesoscale modeling techniques to examine the impact trends and mechanisms of the particulate medium on shock wave attenuation. A two-dimensional (2D) geometric model of the particle layer was created, taking into account random particle distribution and pore size variability. Subsequently, a corresponding finite element (FE) model was derived using a mapped grid algorithm and the porosity control method. Numerical simulations based on the mesoscale model were conducted to analyze the propagation and attenuation of shock waves in the gravel particle layers, leading to a systematic exploration of the underlying attenuation mechanisms. The results indicate that multiple complex reflections among particles significantly influence the propagation path of the shock wave, which is primarily responsible for reducing the overpressure peak and extending the duration of the shock wave. The movement of particles has few effects on shock wave attenuation, while the material properties and friction of the particles can be considered negligible in this context. Furthermore, altering the porosity of the particle layer affects the propagation path of the shock wave, thereby influencing its attenuation characteristics.