Widespread and ineffective dye treatment in aquatic environment leads to serious pollution problems, threatening ecology and human health. Herein, manganese cerium bimetallic oxide cathode material (MnCeOx@GF) was prepared by hydrothermal method combined with calcination, and the electrochemical Fenton degradation performance of a typical dye Rhodamine B (Rh B) was investigated. The results show that the degradation of Rh B by MnCeOx@GF can reach 96.5 % within 2 h in acidic environment and continue to perform effectively after 4 repeated experiments. Combined with SEM and electrochemical test results, it can be seen that the bimetallic composite oxides formed by manganese and cerium on the surface of the support can effectively enhance the catalytic activity of the material, the addition of cerium changes the morphology of manganese oxides and promotes the generation of multiple valence composite oxides of transition metals, and improves the degradation of Rh B. Based on the free radical masking experiments, hydroxyl radical (·OH) is the main active substance in the electro-Fenton degradation process. This work not only provides a way to design and manufacture cathode materials for in situ electrosynthesis of H2O2, but also provides an important reference for improving the reusability of cathodes for sustainable dye wastewater treatment.