[Background] Superficial mycosis cases have been increasing year by year and the pathogenic fungi have become one of the major threats to human health. [Objective] This paper aims to explore the inhibitory effect of dictamnine (DIC) on Trichophyton mentagrophytes and the underlying mechanism. [Methods] Transcriptome sequencing was performed on T. mentagrophytes and T. mentagrophytes after the action of DIC by high-throughput sequencing technology, processing and bioinformatics analysis of the sequencing sequence, sequencing quality evaluation and sequence annotation. By comparing with the control group, differentially expressed genes were identified, and then GO function significance analysis and KEGG metabolic pathway analysis were performed. [Results] The minimum inhibitory concentration (MIC) of DIC on T. mentagrophytes was 50 μg/mL. A total of 360 differentially expressed genes (DEGs) were identified between the control group and DIC high-dose group (265 up-regulated and 95 down-regulated), and the expression of MFS1, KU70, KU80, L2, cpaT, MFS2, VdtG and patC was significantly different. The DEGs were mainly involved in the GO terms of ribosome, mitochondrial membrane, antioxidant activity, toxin metabolic process, single biological metabolic process, secondary metabolic process, primary active transmembrane transporter activity, and active transmembrane transporter activity. The changes in the KEGG metabolic pathway mainly focus on enrichment pathways such as ABC transport, membrane transport barriers, glutathione metabolism, DNA replication and repair changes, meiosis, oxidative phosphorylation and pyruvate metabolism disorders, and related genes are all There is a significant change (P<0.05). [Conclusion] DIC inhibits T. mentagrophytes by influencing DNA replication, expression, and repair, energy metabolism, ABC transport, and other pathways of the fungus.