Bergenia purpurascens, a medicinal alpine plant, exhibits remarkable stress resilience. WRKY transcription factors are central regulators of plant stress responses, yet their family in B. purpurascens remains uncharacterized. Here, we identified 57 BpWRKY genes from B. purpurascens transcriptome data. Expression analysis revealed 11 BpWRKY genes differentially expressed under cold stress, with BpWRKY13 showing the strongest induction. To investigate its function, we overexpressed BpWRKY13 in Arabidopsis thaliana. Transgenic plants displayed significantly enhanced cold tolerance, evidenced by reduced leaf damage, increased survival, and elevated accumulation of proline and soluble proteins. Furthermore, transgenic plants exhibited increased activity of antioxidant enzymes and upregulation of cold-responsive genes. These findings indicate that BpWRKY13 confers cold tolerance by promoting osmoprotection and activating antioxidant defense mechanisms. This study provides a crucial foundation for understanding the BpWRKY gene family and highlights BpWRKY13 as a key regulator of cold resistance in B. purpurascens.