To verify the protective effect of circDNAJB6 on Bronchopulmonary dysplasia (BPD) cell and animal models and to explore the possible mechanism of its protective effect. The function of circDNAJB6 was investigated at the cell and animal levels. Nuclear and Cytoplasmic RNA extraction kits and fluorescence in situ hybridization (FISH) were used to explore the distribution of circDNAJB6 in cells, and the potential mechanism of circDNAJB6 was verified by q-PCR, luciferase assays and rescue experiments.CircDNAJB6 is abundant in breast milk exosomes. Overexpression of circDNAJB6 can ameliorate damage in BPD models caused by hyperoxia exposure in vivo and in vitro. Mechanistically, circDNAJB6 can target the downstream DNAJB6 gene and promote the transcription of DNAJB6, exertive a protective effect on the experimental BPD model. Our results showed that circDNAJB6 alleviated damage and inhibited the proliferation of alveolar epithelial cells in the BPD model by promoting transcription of parent gene DNAJB6. Human milk exosome-derived circDNAJB6 provides new directions for preventing and treating BPD.