In recent years, with the increasing awareness of medical checkups among people with high risk of liver cancer and the combined application of liver cancer markers, ultrasound, CT and MRI, early diagnosis of liver cancer has become possible, and patients with “small liver cancer” with tumor diameter less than 3 cm are more and more common in clinical practice. According to the international authoritative guidelines and the 2019 edition of the “Standard for the Treatment of Primary Liver Cancer” of the Ministry of Health of China, the recommended treatment methods for patients with “small liver cancer” are liver transplantation, surgical resection and ablation therapy. For patients with small liver cancer, liver transplantation can achieve the effect of radical cure. However, liver transplantation is complex, technically demanding, and the source of liver is scarce, the cost of transplantation is high, and long-term immunosuppressive drugs are required after surgery, which is a great challenge to patients and families. Surgical resection is also applicable to patients with small hepatocellular carcinoma, especially surgical resection by laparoscopic technique has the characteristics of small wound, less bleeding and fast recovery. However, the ability to perform laparoscopic surgical resection is closely related to the location of the tumor. Compared with liver transplantation, open or laparoscopic surgery, percutaneous tumor ablation is the “minimally invasive” treatment for small hepatocellular carcinoma. Percutaneous tumor ablation is to induce necrosis of tumor cells and local inactivation of tumor tissues by chemical ablation, thermal ablation or cryoablation of tumor tissues through percutaneous puncture under the guidance of ultrasound, CT, MRI and other medical imaging devices. The inactivated tumor tissue does not need to be removed, but will gradually shrink and become a scar, and the efficacy is equivalent to surgical resection. The most commonly applied clinical ablation treatment for liver cancer is mainly thermal ablation, including radiofrequency ablation, microwave ablation, laser ablation, high-energy focused ultrasound and irreversible electroporation (nano-knife). During the treatment process, medical imaging equipment “navigates” the surgery, precisely locates the tumor, and eliminates the tumor with maximum protection of organ and tissue functions, so it has the characteristics of less trauma, better efficacy, shorter recovery period and less complications. Compared with surgical resection, what are the advantages of percutaneous ablation for small liver cancer? For liver cancer with tumor diameter less than 3 cm, ablation is effective and less invasive, without opening the abdomen, avoiding the trauma of major surgery; 2. 5. Ablation therapy can be repeated, which is especially suitable for multiple recurrent tumor lesions; 6. 1.Patients with small hepatocellular carcinoma who cannot undergo surgical resection due to heart, lung and liver function 2.Recurrent hepatocellular carcinoma, metastatic hepatocellular carcinoma and multiple lesions (less than 3 cm in diameter and within 3 lesions) after surgery 3.Patients who are old and frail and refuse surgical operation. 4.Hepatocellular carcinoma with tumor size of 3-7 cm that cannot be removed surgically can be combined with interventional therapy to improve tumor control rate. 5.For metastatic liver cancer (such as colorectal cancer, lung cancer, breast cancer, sarcoma, neuroendocrine cancer liver metastasis) with poor effect of conventional treatment or treatment failure, ablation therapy can be performed on liver metastases in stages to achieve tumor reduction effect. After nearly three decades of development, tumor ablation technology has been relatively perfected and the scope of clinical application has been expanded, and it has been recognized by more and more clinicians and patients as an important way of comprehensive treatment for liver cancer. Although percutaneous tumor ablation has the advantages of low trauma, high repeatability, wide indications and precise treatment, as an invasive treatment technique, if the indications are not strictly mastered and the technique is not operated properly, it may cause serious complications, such as bleeding (peritoneal and abdominal cavity), adjacent visceral damage, biliary tract damage, infection, fluid pneumothorax and so on. It is still classified as a “restricted medical technique” in China and requires high qualifications and technical water of medical institutions, equipment and personnel. Adequate preoperative evaluation, close monitoring during and after surgery, and timely detection and management of complications are very important. Only in this way can liver cancer ablation therapy better benefit the majority of liver cancer patients and prolong their survival.