In the treatment of colon cancer, there are three types of chemotherapy drugs: the first drug is oxaliplatin or platinum oxalate; the second drug is fluorouracil or fluorouracil derivatives such as capecitabine or siroda; the third drug is irinotecan, also known as CPT-11; there are two other targeted therapies involved in the treatment of colon cancer, one is anti-angiogenic bevacizumab; the second drug is EGFR monoclonal antibody Epiduo. The second drug is the monoclonal antibody of EGFR, Ebestos. These two targeted agents and three chemotherapeutic agents in different combinations play a major role in the treatment of colorectal cancer. Commonly used regimens are the FOLFOX regimen or the FOLFIRI regimen, and the FOLFOXIRI regimen, which is a combination of three drugs. For patients with advanced disease, chemotherapy combined with targeted therapy is preferred to achieve a more desirable treatment effect. In recent years, there have been significant advances in immunotherapy for colon cancer. Patients with colon cancer are examined for relevant genes, including microsatellite instability or mismatch repair genes, and colon cancer is divided into two types, the first with defective mismatch repair gene abnormalities and the second with high microsatellite instability. Patients have limited effect of chemotherapy, but after treatment with immunotherapy, such as PD-1 monoclonal antibody, which is a detection point inhibitor, there is a good effect, which can effectively prolong the survival of patients and improve the response rate of patients, and can improve the treatment effect. Also some stage II patients with mismatch repair gene abnormalities have poor results with fluorouracil-based chemotherapy drugs, and immunotherapy becomes a very important treatment option for this group of patients.