In this study, we have demonstrated the first report on Ag nanoparticles doped on Graphene - Ba2GaInO6 (G-BGI@Ag), which was synthesized by a simple hydrothermal process for improving the counter electrode (CE) in dye-sensitized solar cells (DSSCs). Ag noble metallic nanoparticles can improve chemical and electronic properties by the localized surface Plasmon resonance effect. Therefore, the different atomic percentages of Ag (2-6 wt%) on G-BGI@Ag were studied. The 6% G-BGI@Ag showed an excellent power conversion efficiency (PCE) at 9.90%, which was similar to the Pt CE under the same conditions. The functional groups of G-BGI@Ag were also studied by use of the Boehm titration method. This was because of its enhancement to the adsorption properties and reactivity levels. Moreover, the positive synergistic effect between the BGI@Ag and graphene of the composite exhibited multifunctional characteristics of high photo activity, which could serve as a guideline in photovoltaic high-efficiency multifunctional devices.