T3N0MX of rectobasal junction adenocarcinoma suggests that the tumor is in the early-middle or late stage, which needs chemotherapy, but in the early-middle stage, it is suggested that surgical resection should be the mainstay, and adjuvant chemotherapy should be carried out after surgery, and chemotherapy should be the mainstay in the late stage. Rectosigmoid junction adenocarcinoma generally refers to cancer originating at the junction of rectum and sigmoid colon, which is a kind of malignant tumor of digestive system. T3N0MX refers to the clinical stage of the tumor, which suggests that the tumor is in the early-intermediate or advanced stage. Patients need chemotherapy, but in the early and middle stages, surgical resection is the main treatment, and chemotherapy is used to enhance the curative effect after surgery. It is recommended that patients go to local regular hospitals for consultation and standardized treatment under the guidance of doctors. During the treatment period, we should maintain a good mood and avoid excessive stress. Diet should be light and nutritional intake should be strengthened appropriately to provide nutritional support for the body. Regular review after surgery to avoid recurrence.