[Objective] To study the effect of ferulic acid on the laccase activity of Dichomitus squalens and its molecular mechanism, providing a theoretical basis for microbial degradation of aromatic compounds. [Methods] Ferulic acid was added to the synthetic medium at different concentrations to investigate its effects on the growth of D. squalens and laccase activity. Transcriptomic and proteomic analyses were performed to examine the changes in laccase transcription and protein expression levels induced by ferulic acid. The lcc3 gene was knocked down using RNAi technology, and the impact on laccase activity and the ability to degrade various aromatic compounds was assessed. A self-constructed dual-luciferase system based on Gaussia luciferase and Nano luciferase was employed to identify the core promoter region of the lcc3 gene. [Results] An appropriate concentration of ferulic acid can significantly enhance laccase activity in D. squalens. Transcriptomic and proteomic analyses revealed that the transcription and expression levels of the lcc3 gene were markedly up-regulated under ferulic acid induction. In the lcc3-gene-knocked-down strain, both laccase activity and the ability to degrade various aromatic compounds decreased significantly, confirming that lcc3 is a key gene for laccase-related activities in degrading aromatic compounds in D. squalens. Moreover, the dual-luciferase system successfully identified the core promoter region of the lcc3 gene. [Conclusion] This study first revealed that ferulic acid can induce D. squalens laccase activity and clarified the molecular mechanism. It was also proved that lcc3 is a key gene for ferulic acid-induced laccase activity and degradation of aromatic compounds in D. squalens. Identifying the core promoter region of lcc3 lays a foundation for gene expression regulation research, and these findings offer theoretical support for using microbial laccases to degrade aromatic compounds.