1.Surgical colorectal cancer treatment: The only radical treatment for colorectal cancer is to remove the cancer at an early stage. If cancer metastasis is found during the investigation, but the lesion can still be free, the loess should be removed to avoid intestinal obstruction in the future; on the other hand, the cancer often has erosion, blood oozing or secondary infection, which can improve the general condition after removal. For those with extensive cancer metastasis, if the diseased intestinal segment can no longer be removed, palliative surgery such as fistula or shortcut should be performed. 2.Chemical colorectal cancer treatment: After radical colorectal cancer surgery, there are still about 50% cases of recurrence and metastasis, mainly because the hidden metastases are not detected before surgery or the lesions are not completely removed during surgery. Therefore, before dissection surgery, intra-intestinal chemotherapy or preoperative enema administration for rectal cancer can stop the spread of cancer cells, kill and destroy them. Continuing chemotherapy after surgery has the potential to improve the 5-year survival rate after radical surgery. Chemotherapy for colorectal cancer takes 5-fluorouracil as the drug of choice. It is usually administered intravenously once a day for 5 days, and then the dose is halved and administered every other day until obvious toxicity symptoms such as vomiting and diarrhea appear, with a total amount of 8-10g as a course of treatment. This method is slightly less reactive and is suitable for outpatient treatment. For those with liver metastases, 5-fluorouracil may be given daily, orally in divided doses, which is less effective than intravenous drugs. Combination chemotherapy is mostly advocated, but there is no established regimen. Some people suggest the MFC regimen, i.e., 5-fluorouracil, mitomycin, and cytarabine in combination, which is administered intravenously twice a week for the first two weeks and once a week thereafter, for a total of 8 to 10 times as a course of treatment. In addition to gastrointestinal reactions, bone marrow suppression is also seen as a symptom of chemotherapy toxicity, which must be closely observed. In addition, the commonly used chemotherapy drugs include furanyl fluorouracil, eflornithine, cyclophosphamide, dicloyl nitrosourea, cyclohexyl nitrosourea and metacyclic nitrosourea, etc. 3.Radiotherapy: The efficacy is not yet satisfactory. It is believed that: ① Pre-operative radiotherapy can shrink the tumor, improve the resection rate, reduce regional lymphatic metastasis, intraoperative cancer cell dissemination and local recurrence; ② Post-operative radiotherapy: for radical cases, if the tumor has penetrated the intestinal wall, invaded local lymph nodes, lymph vessels and blood vessels, or if there is tumor remaining after surgery, but there is no distant metastasis, post-operative radiotherapy is appropriate; ③ Radiotherapy alone: for advanced rectal cancer cases, small dose radiotherapy can sometimes have the effect of temporary hemostasis and pain relief. 4.Cryotherapy: Cryotherapy is to use refrigerant liquid nitrogen to fully expose the tumor through anoscope, and then select cannonball type freezing head of different sizes to contact the tumor tissue, which can effectively kill and destroy the tumor tissue. It can reduce the patient’s pain and avoid making artificial anus, and can obtain satisfactory curative effect with chemotherapy. 5. Symptomatic and supportive therapy: including analgesia and nutrition.