Rectal cancer patients with KRAS mutation can be treated precisely with corresponding targeted drugs, but at present, there is no targeted drug for KRAS target, so targeted drugs combined with chemotherapy are often used in clinic. In rectal cancer, KRAS is the most common mutation among RAS subgroups, about 40% of patients will have KRAS mutation, and then targeted drugs can be used in combination with chemotherapy for treatment. Targeted drugs are preferred to bevacizumab, followed by regorafenib and other chemotherapeutic drugs such as platinum drugs. Bevacizumab is mostly used for metastatic intestinal cancer, advanced non-small cell lung cancer, hepatocellular carcinoma, etc. It has adverse reactions such as bleeding, bone marrow suppression, etc., and is prohibited in case of allergy to the drug. Regorafenib is mainly used for patients with metastatic colorectal cancer after previous chemotherapy, with adverse reactions such as bone marrow suppression, bleeding, loss of appetite, etc., and is prohibited for those who are allergic to the drug. For specific treatment of rectal cancer patients, it should be used under the guidance of experienced oncologists to avoid adverse effects.