The distant metastasis of colorectal cancer is mainly in the liver, and about 50% of patients will have liver metastasis, and 30% of patients have occult microscopic liver metastasis that cannot be detected by ultrasound or CT before surgery. 85% of the lesions with intrahepatic metastasis are multiple. Then how to treat colorectal cancer once liver metastasis occurs? One of the clinically accepted methods is surgical resection, but only few patients are suitable for surgical resection, and 70% of them will recur after surgery. For patients who cannot undergo surgery or cannot accept surgery and recurrence, another treatment method is to do argon helium ultracold knife minimally invasive targeted surgery, which can eliminate the tumor load quickly without surgery and can also achieve the purpose of treatment. For patients who cannot be handled by surgery or to prevent metastasis after surgery, only chemotherapy can be continued again, but the effect is generally not satisfactory. Then, is there any better treatment method? Patients with postoperative colorectal cancer and postoperative metastasis can receive synergistic anti-cancer effects, reduce the toxic side effects of chemotherapy, enable patients to pass the chemotherapy period smoothly, improve the efficacy and long-term survival rate, and reduce tumor recurrence by combining biological therapy techniques, such as biological cell therapy and biological targeted therapy, during the chemotherapy process. Biological therapy is an important tool in the postoperative comprehensive treatment of gastrointestinal tumors. On the one hand, postoperative patients are weak, and continuous chemotherapy also brings damage to patients’ body. Biological therapy can repair this in time, increase the sensitivity of tumor to chemotherapy drugs, reduce toxic side effects, and enable chemotherapy to be completed successfully. On the other hand, biological therapy can remove cancer cells that cannot be removed by chemotherapy drugs or left behind, and remove cancer cells more completely. However, the combination of biological therapy and chemotherapy is not a simple combination, but an organic combination of the two methods, which should take into account the advantages of both sides, as well as the scientific coordination in terms of treatment time and sequence.