Abstract. Within the framework of the model of non-stationary motion of a multiphase multicomponent mixture, a numerical simulation of a two-dimensional axisymmetric non-stationary motion of a dispersed three-phase reacting mixture of two-component gas, particles of unitary fuel and homogeneous inert particles is given. The influence of inhomogeneity of inert particles on the interruption of the propagation of heterogeneous detonation waves in monodisperse gas suspensions is studied.