If the condition of rectal cancer is more serious in the early stage and surgery cannot completely relieve it; if the lesion location is relatively low, it is possible to do chemotherapy first before surgery. 1. When the stage of rectal cancer is relatively backward, it is easy to cause incomplete resection through surgery, so it is necessary to lower the stage through preoperative chemotherapy first, reduce the volume of tumor and lower the difficulty of surgery, and then do resection treatment through surgery, and then assist chemotherapy after surgery to prevent recurrence and metastasis. 2. When the location of rectal cancer mass is relatively low, it is relatively difficult to operate, so it is necessary to reduce the scope of lesion through chemotherapy first, and then perform resection through surgery, which can better achieve the purpose of complete resection. Regular review is needed after surgery for rectal cancer, once there are soft tissue lumps in the operation area and abnormal defecation, it is necessary to consult doctor for observation in time, and carry out standardized treatment under the guidance of clinicians.