To further explore the usefulness of bioelectrochemical systems(BES)in promoting the municipal wastewater treatment, the influence and mechanism of the emerging pollutant dibutyl phthalate(DBP)on electroactive biofilms(EABs)were investigated. Using the electrochemical workstation, scanning electron microscope, confocal laser scanning microscope, high-throughput sequencing, and other methods, this study analyzed the effect of DBP concentration on the electrochemical activity, main components, microscopic morphology, spatial structure, and microbial community structure of EAB. The results showed that under the condition of high concentration DBP(10 mg/L), the maximum output voltage and power density of BES were 0. 24 V and 113. 34 mW/m², respectively, which were 33. 33% and 31. 47% lower than those under a low concentration DBP(1 mg/L). The measurement results of protein and polysaccharide in biofilms indicated that high concentrations of DBP stimulated the secretion of β-polysaccharide and showed a strong blue signal on the laser confocal image, while the contents of protein and α-polysaccharide did not change significantly. In addition, the microbial community analysis of EAB under different concentration DBP showed that Petrimonas and Aquamicrobium were the dominant genera under high concentration of DBP. This research also showed that DBP will inactive the electrochemical performance of EAB, and Petrimonas and Aquamicrobium play an important role in the process of biofilm against DBP toxicity.