Argon-helium ultra-low temperature cryotherapy (also called argon helium knife) is one of the new technologies for tumor treatment that has been rapidly promoted in recent years. It is an effective treatment measure to directly destroy tumors with real-time monitoring under the guidance of CT, B-ultrasound, X-ray, etc. It has many advantages such as less trauma and fewer side effects. At present, it is mainly applied to liver cancer, lung cancer, prostate cancer, kidney cancer and so on. Liver cancer is one of the more common tumors in China, which often starts insidiously and progresses rapidly. Many patients have hepatitis, cirrhosis and other manifestations, and there are many comorbidities at the onset, and they often cannot tolerate surgery or have recurrence in the short term after surgery, which makes treatment more difficult. As one of the comprehensive treatment methods for liver cancer, argon helium ultra-low temperature cryotherapy is mainly applicable to the following patients: 1. early stage small liver cancer found by physical examination. 2.Middle and late stage hepatocellular carcinoma that cannot be treated surgically or unwilling to be treated surgically and need to rapidly reduce tumor load and improve life quality. 3.Post-operative recurrence with more limited tumor. 4.Colon cancer, gastric cancer and other combined liver metastases. 5.Those who need to increase the treatment effect by combined interventional therapy.