Dispersion of Particle-laden Jet in Supersonic Crossflow (PJSC) is an essential process in many applications, experimental study on which, however, has rarely been reported. In order to gain physical insights into PJSC, a specialized experimental setup capable of producing a supersonic crossflow at Mach 2.6 and a particle-laden jet with particle mass loading up to 60% is developed. Visualization of the particles motion is achieved with the help of high-speed planar laser scattering technology. The dispersion characteristics of PJSC within a supersonic channel structured by cavity are systematically analyzed through six experimental cases. The results indicate that the vortices have a significant influence on particle dispersion, leading to preferential concentration of particles, i.e. particle clusters. The particle dispersion is summarized as the “scale dispersion” pattern. The primary pathways for particles entering the cavity are identified as the shear layer above the cavity and collisions at the cavity rear edge. Among the studied factors, the momentum flux ratio exerts the most substantial influence on the dispersion process. Importantly, a reduction in the injection distance is correlated with less particles entering the cavity. The insights gained from this research provide essential references for furthering understanding particle dispersion mechanisms in supersonic flows and developing highly accurate numerical models.