Ultrasound has evolved through A-ultrasound, B-ultrasound, doppler ultrasound (i.e., color ultrasound), ultrasonography, and three-dimensional ultrasound. Currently, the most commonly used ultrasound examinations are color ultrasound. The application of color ultrasound is very wide, especially in the examination and treatment of substantial organs, such as the liver. With color ultrasound, our hepatic surgeons can understand the size and texture of the liver, the location and internal diameter of the major blood vessels, as well as the blood flow rate and flow. Most importantly, the location, nature, size, and relationship to the surrounding organ vessels of the lesion can be examined. Ultrasound combined with other imaging studies such as CT and MRI can be very accurate and effective in detecting the size, location, and nature of occupying liver disease. Ultrasound is fairly inexpensive and therefore can be used for screening of large populations. Ultrasound is also very accurate in the hands of experienced physicians and can detect many early stage patients and even has a role that cannot be replaced by other tests. A procedure the other day fully illustrated the superiority of color ultrasound. A patient had previously undergone an operation for a liver tumor. During the post-operative review, new tumors were found in the liver, one of which was 1.5 cm more definite, while the other, 7 mm, was not very certain due to its deeper location. The preoperative ultrasound findings were similar. The indications for surgery were very clear and the key was the confirmation and removal of that small tumor. After full communication with the family, the surgery was started electively. Due to the reoperation, the abdominal cavity was very adherent and the liver surface had a lot of scar tissue attached to it, which was no longer smooth and soft, but hard in texture. After removing the larger tumor, we could not feel the small one. Was it not there, or was it not found? This is where the color ultrasound machine comes into play. An intraoperative ultrasound machine is an ultrasound probe that is placed on the liver during surgery to examine the liver. We also had a senior doctor from the color ultrasound room assist us. The probe moves sequentially from top to bottom, left to right, looking for that tumor. It was a bit like looking for a mine with a mine detector on a battlefield. Finally, the tumor was found. The second problem was in front of us. The tumor was deep and removal of the tumor would require removal of a large piece of liver, which had already been removed in the previous surgery. The risk of hard resection is very high, but we can’t do without it. In addition to resection, we have another tumor treatment technology, which is radiofrequency ablation. The principle is to insert a radiofrequency needle into the tumor, introduce heat and burn the tumor at high temperature, which can achieve the treatment effect of tumor elimination without removing the liver. But the tumor is so small and so deep, how to pierce the tumor? This is where the color ultrasound machine shines once again. The ultrasound machine can see the tumor and the RF needle. In the hands of experienced doctors, we can accurately stab the tumor and burn the tumor under the guidance of the ultrasound. That scene is like the probe of a missile guiding the missile to blow up the target. This is the application of science and technology in medicine to help doctors defeat diseases. It’s like an army equipped with advanced weapons to defeat the enemy.