Abstract： Young breast cancer patients are associated with high-risk clinicopathological features and poor prognosis, leading to unique medical and psychosocial needs and calling for special attention in clinical practice. In recent years, the incidence of young breast cancer has gradually increased worldwide, and several international committees have formed some consensuses on young breast cancer management. In China, there is a higher proportion of young breast cancer patients with younger age of onset and different clinical problems, lacking clear evidence-based medicine and guidelines. Based on the characteristics of young breast cancer and present situation of diagnosis and treatment in China, more than 100 experts from multiple specialities including surgery, internal medicine, radiotherapy, gynecology and reproduction had a deep discussion around the hot topics in young breast cancer, involving germline BRCA1/2 gene mutation, chemotherapy, endocrine therapy, fertility preservation and gynecological conditions, and formulated the 'Expert consensus on the diagnosis and treatment of young breast cancer in China (2022 Edition)'. This consensus is made according to the progress of clinical research worldwide and combined with the clinical practice in China, with the aims of standardizing and optimizing the diagnosis and treatment of young breast cancer in China, promoting the development of relevant clinical research, and further improving the prognosis and quality of life of young breast cancer patients.