In this study, an aerobic denitrifying bacterial strain with phenol as the only carbon source was used to make a composite bacterial agent and combined with the SBR process to strengthen the activated sludge treatment of simulated phenol-containing wastewater, and to analyze the effect of the composite bacterial agent on the efficacy of simultaneous nitrogen removal and phenol removal. The results showed that the phenol loading capacity of the SBR system was improved after biofortification, and the ammonia nitrogen, phenol and total nitrogen removal rates were increased by 5.17%, 6.16% and 9.49%, respectively. The bacterial agent used for biofortification belongs to the phylum Aspergillus, and the high-throughput sequencing results showed that its abundance tended to increase in the fortified reactor, indicating that the composite bacterial agent has a good adaptive ability in the system, and it may play a role in the process of nitrogen removal and phenol removal.