Frost damage to apple flowers significantly affects both the quality and yield of apples, potentially leading to substantial economic losses. This study investigates the application of the environmentally friendly plant hormone 24-epibrassinolide (EBR) on apple flowers to assess its effects under frost stress conditions. The findings indicate that exogenous EBR treatment maintained favorable flower morphology, mitigated pistil browning, and reduced ion leakage. Furthermore, EBR enhanced the ICE-CBF-COR signaling pathway and increased proline accumulation by modulating gene expression and enzyme activity involved in proline metabolism, promoting osmotic adjustment ability of cells. Furthermore, EBR treatment retarded the increase of H