Abstract: Bubble discharge enables efficient plasma-liquid interactions and has promising applications in energy, environment, biomedicine and other fields. The efficiency of bubble discharge plasma-liquid interaction is highly dependent on the electrode structure. The addition of dielectric layers as a way of adjusting the electrode structure is a common means of regulating the discharge in gaseous discharges such as dielectric barrier discharges; however, in bubble discharges with more complex systems and more interfering factors, the influence of the dielectric layer on the discharge characteristics and plasma-liquid interactions is unclear. This study investigates the influence of the high voltage electrode covering dielectric on the bubble discharge characteristics and plasma-liquid interaction. The results indicate that the discharge in the single-dielectric structure is a mixed mode of filamentary discharge in the middle region and spark-like discharge in the tip region. Meanwhile, a diffuse discharge is presented in the dual-dielectric structure, whose high voltage electrode is covered with a dielectric layer. The covering dielectric weakens the polar effect but promotes the accumulation of memory charge, while the difference in discharge morphology is the result of the combined effect of the electric and flow fields. Under the premise of higher plasma activity, the larger discharge-solution contact area of the single-dielectric structure further improves the efficiency of the plasma-liquid interaction, producing a hydrogen peroxide concentration of 32.0 mg/L, much greater than the 0.9 mg/L of the dual-dielectric structure. More reactive species and stronger physicochemical effects generated in the discharge process will facilitate more significant changes in the solution properties in the single-dielectric structure.