Gas diffusion electrodes (GDEs) were selected for the reactive brilliant red X-3B simulated wastewater treatment, perovskite oxide LaNiO3 as the catalyst. And a satisfying degradation effect was achieved. The optimal conditions for the catalyst preparation with sol-gel method were 1.5 as the molar ratio of citric acid and metal ions, 10 as the pH, and 750 °C as the roasting temperature. The optimal conditions for the electrodes preparation were 1 g pore-forming agent, 0.6 g catalyst, 3 g PTFE and 300 °C as the roasting temperature. Scanning electron microscope, X-ray diffraction were applied to analyze the performance of catalyst and electrodes, and the results were satisfying.