The thermal decomposition method was used to prepare composite electrodes of the Ruthenium oxide-Iridium oxide-Graphene (RuO2-IrO2-G). Scanning Electron Microscopy (SEM), X-ray diffraction analysis (XRD), and electrochemical tests were used to study the influence of different annealing holding time on the surface morphology, phase composition, and capacitive performance of the coatings. The results showed that more and more RuO2, IrO2 nanoparticles were observed on the surface and cracks of the coating as the annealing holding time increasing. The RuO2-IrO2-G/Ti electrode was obtained by annealing for 5 h. The coating of the electrode consists of a certain amount of amorphous phase and nano-crystalline phase, and it had good electronic conductivity and ionic conductivity. At the same time, the electrode was prepared at 5 h had the largest specific capacitance of 778.46 F/g, which increased by 430.89 F/g than the electrode was prepared at 1 h. In addition, the electrode also had superior capacitance performance, capacitance retention and power characteristics.