The development of imaging equipment and technology has prolonged the doctor’s vision so that we can precisely see the internal structure of the human body without opening the human tissues through surgery; while the development of medical devices has prolonged the doctor’s hands so that we can accurately reach the lesion site for treatment without exposing the human tissues and organs. Under imaging guidance, minimally invasive interventional treatment can be divided into two categories, vascular and non-vascular, in terms of treatment technology; the main content of vascular interventional treatment is local perfusion chemotherapy and embolization of tumors through selective intubation of blood vessels, while the main content of non-vascular intervention is ablation treatment of percutaneous perforated tumors and implantation of radioactive particles. 1.Chemical ablation: Under the guidance of imaging equipment, the tumor tissue is punctured percutaneously and the ablative agent is injected directly into the tumor to achieve the purpose of in situ inactivation of tumor. Chemical ablation is suitable for primary and metastatic tumors in various parts of the body, benign and malignant adrenal tumors, primary liver cancer with lack of blood supply, metastatic liver cancer, lung cancer, pelvic tumors, etc. or incomplete filling of iodine oil in the lesion and lymph node metastasis after TACE of liver cancer. The commonly used ablative agents include tumor cytotoxic agents (various chemotherapeutic drugs), protein coagulants, etc. 2.Physical ablation: The lesion is punctured under image guidance, and the lesion is necrosed by the cold or heat effect of physics. Physical ablation is also divided into thermal ablation and cold ablation. The commonly used thermal ablation methods include radiofrequency ablation, microwave ablation and laser ablation. Thermal ablation: Tumor cells are very sensitive to temperature and cannot tolerate temperature above 60℃, and above 70℃, they will all apoptosis. The internal temperature of whole body thermotherapy cannot exceed 40℃ or above, so it has limited therapeutic effect on tumor. In situ inactivation of tumor can be achieved by generating high temperature inside the tumor through physics. Among thermal ablation treatments, radiofrequency ablation is the most widely used. Its basic principle is to introduce high-frequency oscillating current into tumor tissues through ablation electrodes, so that the ions and polarized molecules of local tissues, with the rapid alternation of current alternating direction, generate oscillation leading to frictional heat generation in tissues, and the heat comes from the tissues themselves not from radiofrequency electrodes. When the local temperature reaches 50℃, the tissue cells start to die in 4-6min; when the temperature exceeds 70℃, the cells die immediately; when the temperature reaches 100℃, the cell membrane is dissolved, the intercellular water evaporates, and the tissue disintegrates and carbonizes. The ablation area of tumor is spherical or oval, and the maximum diameter of ablation at one time can be up to 55mm at the current multi-needle ablation electrode. the temperature of RFA treatment requires complete necrosis of tumor cells and avoid vaporization and charring of local tissues, and the tissues are gradually removed and absorbed by human body after ablation. Radiofrequency thermal ablation as a minimally invasive treatment technology has been widely used in the treatment of liver, kidney, prostate and other substantial organ tumors, and has achieved ideal efficacy. 3.Laser ablation: This technique is to send/scatter laser light through a 0.4mm diameter optical fiber in the lesion and transform it into heat energy to cause coagulation and necrosis of tumor cells without damaging the surrounding tissues. The laser energy can cause spherical coagulation necrosis around the laser beam. The extent of laser ablation is not only related to its energy accumulation, but also depends on the blood supply of the tumor and the vasodilatory response of the surrounding normal tissues. The efficacy of LITT treatment depends on the precise position of the laser probe and the temperature change of the local tumor tissue. Ultrasound, CT, magnetic resonance imaging (MRI), CT-PET and other imaging methods can monitor the range of action of laser intra-stromal thermotherapy. In recent years MRI multi-planar guidance and can show temperature changes and coagulation necrosis, making the operation process more accurate, due to equipment limitations, this technique has not been widely carried out. 4, cryoablation: recent cryotherapy equipment argon helium knife is the use of Joule-Thomson effect, the use of room temperature high-pressure argon gas cooling, the lowest temperature at the tip site can reach -185 ℃, high-pressure helium rewarming, the temperature can reach 70 ℃. Tumor necrosis is accelerated by cycles such as freeze-retemperature. The commonly used probe is an ultra-fine probe with a diameter of 1.47 mm, which allows cryoablation of larger lesions through a combination of multiple needles. The principle of cryogenic freezing is the formation of ice crystals within the interstitial cell. Changes in electrolytes and osmotic pressure inside and outside the cell lead to cell dehydration, damage to the cell membrane, which in turn leads to intracellular ice crystal formation and cell degeneration and necrosis. The intima and basement membranes of microarteries and microvenules swell and break during cryoablation, which leads to extensive thrombosis within the local microcirculation after rewarming, further aggravating tissue hypoxia and promoting tissue necrosis. Cryoablation is the best treatment for larger tumors (diameter >3cm) without any toxic side effects, and the long-term follow-up results prove high survival rate. Radioactive particle implantation: Radioactive particle (seed source) implantation for malignant tumor is an advanced minimally invasive treatment method, which is a kind of brachytherapy, with the advantages of safety, reliability, wide indications and easy operation. It is a new technology of minimally invasive in vivo radiotherapy for malignant tumors, which fully combines advanced image guidance equipment and in vivo brachytherapy technology.