Constructed wetland microbial fuel cells (CW-MFCs) are promising for removing trace contaminants. We investigated using Fe3C as an anodic exogenous electron donor in a CW-MFC to remove bisphenol A (BPA). BPA removal and electricity production were used to evaluate the CW-MFC performance, and bacterial high-throughput sequencing was used to investigate the microbial response. The experimental system removed BPA (91.62 ± 0.85 %), chemical oxygen demand (76.44 ± 2.25 %), total phosphorus (98.40 ± 0.17 %), and ammonium nitrogen (91.62 ± 0.85 %). It also had a high voltage (352.13 ± 31.48 mV) and power density (3.88 mW/m2), and relatively high coulombic efficiency (3.31 %). Fe3C addition enhanced bacterial cooperation and community stability, and increased the abundance of electroactive and ferric ammonium oxidation bacteria (Desulfovibrio and Geobacter). These changes explained the improved water purification effect and electricity production. Fe3C as an anodic electron donor in CW-MFCs is promising for practical applications.