Abstract: Human epidermal growth factor receptor 2 (HER2) is a key therapeutic target for breast cancer. With the wide application of anti-HER2 and HER2 antibody-drug conjugates such as trastuzumab, pertuzumab, trastuzumab emtansine, and trastuzumab deruxtecan, the survival of patients with advanced HER2-positive breast cancers have been significantly improved. However, the subsequent drug-induced interstitial lung disease (DILD) has gradually become an important complication affecting the therapeutic effect and safety. However, the clinical understanding of interstitial lung disease (ILD) caused by this type of drugs is still insufficient, the management lacks unified standards, and the molecular mechanism has not been fully clarified. This study, through two clinical cases of severe DILD, explores the pathogenesis, treatment strategies, risk factors and follow-up monitoring requirements of ILD caused by HER2-targeted drugs, providing a scientific basis for optimizing the clinical diagnosis and treatment plan.