Hepatitis, cirrhosis and liver cancer are highly prevalent in our country. Primary liver cancer occupies the third place among male malignant tumors in China. The radical treatment of liver cancer is also a common concern of the medical community and patients. With the progress of science and technology, more methods are available for the treatment of liver cancer. Radiofrequency thermal ablation has been used for the treatment of primary liver cancer for ten years, and this technology has been widely used in the clinical treatment and research of liver tumors, and has become a more mature technology for the clinical treatment of liver cancer. Radiofrequency thermal ablation is a minimally invasive in situ tumor treatment technique, which is based on the positioning and guidance of electrode needles directly inserted into the tumor with the help of ultrasound or CT imaging technology, and generates high temperature in the local tissues of the lesion through radiofrequency energy, which eventually coagulates and inactivates soft tissues and tumors. The principle is that when the electron generator generates radiofrequency current, the electrode needle causes high speed ion vibration and friction in the surrounding tissues, which is then converted into heat energy and transmitted outward with time, thus causing local tissue thermal coagulation and necrosis and denaturation. The present technique of radiofrequency ablation using a single electrode needle can produce coagulated necrotic foci up to 5 cm in diameter. In clinical observation, the treatment of liver tumors with radiofrequency ablation has excellent results, and the survival rates at 1, 2, 3 and 5 years after treatment are reported to be 94%, 86%, 68% and 40%, respectively, in treating patients with primary liver cancer, and this effect is similar to that of radical surgical resection. At the same time, it has achieved the goal of minimally invasive and radical treatment of liver cancer. Nowadays, there are some changes and controversies in the medical field due to the development of liver radiofrequency treatment for some small liver cancer patients or patients with very severe cirrhosis, but the choice of radiofrequency ablation treatment for these patients is becoming more and more obvious in clinical treatment. Meanwhile, compared with the alcohol injection method, which is the same modality of radiofrequency ablation, clinical results show that radiofrequency ablation achieves a complete tumor necrosis rate of 90% compared with 80% for the alcohol injection method; the average cycle per tumor requires 1.2 for radiofrequency ablation compared with 4.8 for alcohol injection. In comparison, the treatment effect of radiofrequency ablation is better than that of alcohol injection method. What kind of patients are suitable for radiofrequency ablation of liver tumor: According to the characteristics of radiofrequency ablation technology, the scope of radiofrequency ablation should exceed 1cm of tumor edge to achieve complete necrosis of tumor. The range of radiofrequency ablation with one electrode needle is 5cm in diameter. Liver tumors below 3cm can achieve complete coverage of radiofrequency ablation after one electrode insertion, and it is reported that 67% of liver tumors below 3cm have complete necrosis after radiofrequency ablation, which has better treatment effect. However, when the liver tumor is 3-4cm, the electrode needle needs to be adjusted for at least 6 times of RF ablation, and the residual tumor rate and recurrence rate are significantly higher. Therefore, the most suitable patients should have liver tumor less than 3cm and the number of liver tumors should be less than 3. If the size of liver tumor is more than 5cm, it is better to consider surgical resection first. In addition, some patients with severe cirrhosis or poor health condition who cannot tolerate surgical liver resection can also consider radiofrequency treatment for liver tumors. There are roughly three methods of radiofrequency treatment, one is to put electrode needles into liver tumor directly from the surface of liver through ultrasound guidance or CT guidance; the second is to put electrode needles into liver tumor through TV laparoscopy under the direct view of TV during surgery, and also under the guidance of laparoscopic ultrasound; the third is to put electrode needles directly into liver tumor during surgery. This is because the tumor cannot be removed, or the cirrhosis of the liver is too serious to be removed and intraoperative radiofrequency treatment is done, which can also achieve good results. In recent years, we have developed laparoscopic radiofrequency ablation therapy for liver cancer, which makes full use of the advantages of surgical laparoscopy and allows the patient to directly penetrate the liver tumor under television surveillance in a painless state, and the effect is really effective and can separate the organs around the liver to avoid damage to the organs around the liver. The most important point is that the treatment of liver tumor is minimally invasive. The electrode needle of radiofrequency only involves a maximum diameter of 5 cm, which has little effect on the rest of the liver tissue, especially for patients with severe cirrhosis, it is important to preserve as much functional liver tissue as possible. Therefore, it is more suitable for small hepatocellular carcinoma and multiple hepatocellular carcinomas, patients with severe cirrhosis who cannot tolerate surgical resection, and patients with less reaction after treatment can be discharged from the hospital after 1-2 days of postoperative observation in extracorporeal or laparoscopic radiofrequency treatment. Another advantage is that radiofrequency for liver tumor can be repeatedly performed, and the previous stage of radiofrequency does not affect the later treatment, and the same is true for laparoscopic radiofrequency. This eliminates many people’s concern about re-operation. Disadvantages of radiofrequency ablation therapy for liver tumor: Any technology has certain limitations in clinical application. The most important thing for radiofrequency ablation therapy for liver tumor is the size of the tumor. The first choice for such patients should be surgical resection, if they cannot tolerate surgery for physical reasons, they can be considered for radiofrequency treatment of liver tumor. Another reason that affects the effect is the accuracy of RF electrode needle penetration. In theory, it is said that the electrode needle is distributed in each part of the tumor, but in practice, it is affected by various factors such as bad location, judgment of ultrasound image by severe cirrhotic nodules, and equipment, etc., which directly affect the accuracy of penetration and finally have an effect on the effect. Follow-up evaluation of radiofrequency ablation therapy for liver tumors: The postoperative review is generally not applicable to ultrasound observation because it is difficult to accurately judge the extent of coagulation necrosis by ultrasound. If a thick and irregularly enhanced halo around the treated area is found, it indicates that the treatment is insufficient and needs to be treated again. Generally, an enhanced CT examination is performed 1-3 months after surgery, and if a tumor recurrence is found, it can be treated again. At the same time, blood can be drawn to check methemoglobin and other tumor markers dynamically to observe whether there is any elevation, and elevated index also indicates tumor recurrence. Complications of radiofrequency ablation treatment for liver tumor: It is relatively safe to choose radiofrequency ablation treatment for liver tumor, which has little effect on the whole body and light traumatic reaction. The complications after treatment are generally below 5-6%. They may include pain at the treatment site due to peritoneal or diaphragmatic thermal injury caused by radiofrequency, bleeding at the site of liver puncture or subhepatic hematoma, liver abscess at the treatment site, acute cholecystitis if the treatment site is close to the gallbladder, injury to organs around the liver such as colon perforation, etc. As well as tumor implantation metastasis along the perforating needle tract. Medical observation for 1-2 days is needed after treatment to prevent various complications as well as to provide timely treatment when complications are detected.