The stage of malignant tumor with metastasis to organs other than the primary site is stage IV, which is advanced. In the past concept, stage IV means unnecessary surgery and incurable. However, the concept of tumor treatment is now more advanced and innovative. Colorectal cancer, no matter there is liver metastasis at the initial diagnosis or liver metastasis occurs after surgery, may still have the chance of surgery and may still obtain long-term survival or even cure, and the 5-year disease-free survival rate after surgery is 20%. Factors affecting the prognosis of liver metastases from colorectal cancer: whether there are extrahepatic metastatic lesions; whether there are more than 3 liver metastatic lesions; whether the disease-free survival is less than 12 months. 2.Requirements for resection of liver metastases: no residual lesions, incomplete resection or tumor reduction surgery does not benefit patients. 3.Subsequent chemotherapy before and after liver metastasectomy: Several randomized controlled trials showed that surgery supplemented with chemotherapy was associated with significantly longer disease-free survival and a trend toward longer overall survival compared with surgery alone, but did not reach a statistically significant difference (p = 0.088). 4. The sequencing of chemotherapy and surgery: there are two options: resection of liver metastases first, followed by adjuvant chemotherapy; or chemotherapy before surgery, followed by surgery, and then chemotherapy after surgery. These two treatment options have their own advantages and disadvantages, depending on the patient’s specific condition. The advantages and disadvantages of chemotherapy first and then surgery: it is difficult to completely remove multiple or large liver metastases, and chemotherapy first may shrink the liver metastases that cannot be completely removed, making complete removal possible; preoperative chemotherapy can judge the efficacy of chemotherapy by whether the tumor shrinks after chemotherapy, so it can be used to choose a suitable chemotherapy regimen after surgery; the response of liver metastases to preoperative chemotherapy has a certain judgment on survival Prognostic value: Early tumor regression after chemotherapy indicates longer disease-free survival and overall survival. Possible disadvantages: if chemotherapy is not effective, the opportunity of surgery may be lost; liver metastases may be so sensitive to chemotherapy that the lesions disappear on CT after chemotherapy, making it impossible to find the lesions that should be removed during surgery, but in fact the tumor cells are still present in the liver, only too small to be seen by the naked eye; chemotherapy drugs may cause liver damage making postoperative complications higher. Therefore, it is best to limit preoperative chemotherapy to 2 to 3 months and to evaluate the efficacy by imaging methods every 2 months of chemotherapy in order to allow for surgery. The total duration of chemotherapy is approximately 6 months, regardless of the treatment sequence taken.