In this study, 383 differentially expressed genes (DEGs) between the allergic group and the nonallergic group were excavated. Humoral immune response, chemokine-related biological processes, granulocyte-related biological processes, IL-17 signaling pathway, and TNF signaling pathway were found connected with DEGs. The allergic group had significantly higher enrich scores of T cells, T helper cells, TFH, and Th17 cells than the nonallergic group. We acquired 26 rape pollen allergy-associated genes by taking the intersection of key module genes from WGCNA and the DEGs. The functional enrichment results show that rape pollen allergy-associated genes are relevant to processes and pathways like regulation of inflammatory response, transcriptional regulation, lymphocyte differentiation, IL-17 signaling pathway, and MAPK signaling pathway. Then, three characteristic genes were defined by crossing the genes derived from LASSO and SVM-RFE algorithms, including MYADM, PMAIP1, and MLF1. The AUC values of these genes manifested that the three genes had a mighty discrimination power in discriminating allergic samples from nonallergic samples. In conclusion, this study revealed three characteristic genes (MYADM, PMAIP1, and MLF1) in rape pollen allergy, suggesting that they may be potential biomarkers in rape pollen allergy diagnosis and treatment.