Abstract: Hormone receptor positive/human epidermal growth factor receptor 2 negative (HR+/HER2−) breast cancer is the most common breast cancer subtype, accounting for approximately 65%-70% of breast cancers. Endocrine therapy is the cornerstone of adjuvant therapy. Even with standard endocrine therapies, patients may still experience local and/or systemic recurrence. Recently, with the application of cyclin-dependent kinase 4/6 (CDK4/6) inhibitors, significant breakthroughs and advances have been made in the adjuvant treatment strategies for HR+/HER2− early stage breast cancer. Both the MonarchE and NATALEE studies were phase Ⅲ clinical trials evaluating CDK4/6 inhibitors in combination with endocrine therapy for the adjuvant treatment of HR+/HER2- early stage breast cancer. These two studies confirmed that CDK4/6 inhibitors in combination with endocrine therapy significantly prolonged invasive cancer-free survival (iDFS), providing a new option for the intensive treatment of patients at a high risk of recurrence. Based on this, CDK4/6 inhibitors were first recommended for use in treating high-risk HR+/HER2− early stage breast cancer by the 2025 Committee of the Breast Cancer Society guidelines. Despite its established efficacy, further research is needed to determine the optimal treatment duration, long-term survival benefits, safety management, and cost-effectiveness. In this study, we have systematically reviewed the latest medical evidence of endocrine therapy for HR+/HER2− early stage breast cancer, and discussed the precision treatment strategy, and look forward to future directions such as circulating tumor DNA (ctDNA) dynamic monitoring, treatment “escalation” and “de-escalation,” novel drug combination and post-resistance treatment strategies in the adjuvant setting to provide scientific reference for clinical treatment.