Abstract: Breast cancer is the most common malignant tumor in women worldwide. HER2-positive and HER2-low breast cancers are highly aggressive subtypes with poor prognosis. First-line combination therapies targeting HER2 have significantly improved treatment outcomes for patients with advanced and metastatic breast cancer, but resistance inevitably develops. The emergence of antibody-drug conjugates (ADCs) brings new hope for the treatment of advanced HER2-positive and HER2-low breast cancers. This article analyzes the efficacy and safety of key ADC drugs, including adotrastuzumab emtansine (T-DM1), trastuzumab deruxtecan (DS-8201, T-DXd) and other drugs in the treatment of advanced HER2-positive and HER2-low breast cancers. It also reviews mechanisms of ADC resistance and discusses corresponding management strategies, aiming to provide more efficient and personalized treatment options for patients with advanced HER2-positive and HER2-low breast cancers.