Microwave ablation is a minimally invasive treatment that can treat benign nodules as well as malignant nodules. The principle of microwave is to kill the cells of the nodule by heat energy, and then to eliminate the tumor. For example, for benign thyroid nodules, a long microwave needle can be punctured and placed in the center of the nodule under ultrasound guidance. The nodule is then heated by connecting an external device, usually to about 80 degrees for 3-5 minutes, to ablate the nodule. It can also deal with metastatic tumors in the liver. If there are more metastatic tumors in the liver that are not suitable for surgical resection in stage I or II, they can be treated by a minimally invasive method, which is microwave ablation. It can be treated under ultrasound guidance or under laparoscopic guidance. The microwave needle is inserted in the center of the tumor, and then the ablation time is decided according to the size of the tumor, for example, 3 or 5 minutes, and it is enough to observe the yellow color of the tumor surface.