Abstract: In order to develop an efficient and economical treatment technology for dye wastewater, rhodamine B (RhB) was degraded by ultrasonic cavitation microbubble-assisted liquid-phase low-pressure plasma discharge. The performance of this treatment was evaluated. Corresponding results indicated that under identical voltage conditions, the cavitation effect of microbubbles significantly enhanced the treatment efficiency by accelerating the degradation reaction of RhB, therefore notably shortening the decolorization time. Compared with the standalone liquid-phase low-pressure plasma discharge technology, the microbubble-assisted technology can shorten the decolorization time from 3~5 min to 1~2.5 min when RhB concentration ranges from 10 to 50 mg·L⁻¹. Additionally, it achieved a total organic carbon (TOC) removal rate of 90% to 94%, and save over 50% of electrical energy. These results demonstrate that microbubble-assisted liquid-phase low-pressure plasma discharge technology not only effectively enhances the degradation ability towards RhB, but also significantly reduces energy consumption, holding promising potential for broad application in actual dye wastewater treatment.