Abstract: Against the backdrop of accelerated population aging, the prevalence of comorbidities in patients with malignant tumors has risen by 0.54% annually, presenting a significant challenge to clinical oncology. Currently, the awareness of oncology multimorbidities varies significantly among specialists at different levels of healthcare institutions nationwide, and a comprehensive management workflow for patients with cancer and multimorbidities is lacking. Therefore, the Chinese Society of Clinical Oncology Committee of Experts on Cancer Supportive and Rehabilitation Therapy convened a multidisciplinary panel of experts to develop the Chinese Expert Consensus on Oncology Multimorbidity Management (2025 Edition). Aimed at frontline clinicians involved in the diagnosis and treatment of malignant tumors, the consensus addresses 29 core issues in multimorbidities management and guides the standardized, comprehensive management of oncology multimorbidities.