Antibiotics are increasingly polluting the water environment. Sulfadiazine (SDZ), a typical sulfonamides, has attracted the attention of many researchers. In this study, cathode-anode microbial fuel cells (MFC) was conducted to investigate the SDZ degradation performance, in which the graphite felt with high porosity and good electrical conductivity was selected as electrode material. Electrical properties of MFC were also evaluated through power density. Furthermore, the intermediate metabolites of SDZ were detected by UPLC-MS /MS. The biotoxicity of SDZ degradation products was determined using E. coli as the tested bacteria. The results show that the removal efficiency of SDZ (40 mg? L-1) could reach to 98.23% after 5 months. According to the intermediate products, two main degradation pathways of SDZ are deduced, among which benzenesulfonic acid is the main metabolite. The power density curve indicate that the MFC with graphite felt as the electrode material has excellent electrical performance. The toxicity test results demonstrate that the product of SDZ cannot inhibit the growth of E. coli.