[en] The influence of solid packing on the chemical process involved in the solid-liquid-gas three-phase discharge plasma reactor, initiated by a bipolar pulsed power source was studied with indigo carmine (indigo-5,5'-disulfonic acid, IDS) as the probe. Dynamic scanning of the UV-Vis absorption spectrum was used as the analysis method. Experimental results show that addition of solid packing into the water-air two-phase discharge plasma reactor enhances the chemical processes in the reactor. The dielectric properties of the packing materials determine the degree of enhancement. Water treatment performance of the reactor with dielectric spheres is much better than that with conducting materials for the same experimental conditions. In addition, dielectric glass beads have a stronger influence on the chemical enhancement process than ceramic spheres. Decolourization of IDS in the plasma reactor with dielectric packing is a pseudo-first-order reaction. The total organic carbon in the solution decreases during the treatment process