Whether chemotherapy is needed after colon cancer surgery mainly depends on the tumor stage and should also be combined with the patient’s recovery, which can be roughly divided into the following cases: 1. Patients with stage I colon cancer: generally the cancer cells infiltrate shallowly and there is no lymph node metastasis, so chemotherapy is not needed; the five-year survival rate is as high as 80%-90%. 2.Stage II colon cancer patients: generally the patients have deeper cancer cell infiltration, even invading the whole intestinal wall, but no lymph node metastasis. Patients with high-risk factors, such as poor differentiation of tumor cells, presence of vascular or nerve invasion, preoperative intestinal obstruction, and low number of cleared lymph nodes, need chemotherapy, with a five-year survival rate of 60%-70%. 3.Stage III colon cancer patients: the five-year survival rate of these patients is about 30%-70%. In order to improve the five-year survival rate and reduce the recurrence rate, it is generally recommended that patients should undergo about six months of adjuvant radiotherapy and chemotherapy after surgery. 4.Stage IV colon cancer patients: the main purpose of surgery for this group of patients is to deal with complications such as intestinal obstruction, bleeding or perforation, and chemotherapy should be given as early as possible after surgery to control the growth of tumor. Patients with high-risk stage II, III and IV colon cancer need chemotherapy after surgery. Patients who need chemotherapy after surgery need to pay attention to nutrition, maintain a good state of mind and actively cooperate with the treatment, the chances of recovery are still there.