The ultrasonic scalpel is an advanced surgical instrument that uses ultrasound waves to cut tissue. Our department uses ultrasonic knife extensively in thyroid surgery, so that thyroid surgery can be carried out in a safer, more delicate and more effective way. Compared with traditional surgical instruments, ultrasonic knife has the following advantages: 1, small side damage caused by cutting tissue, effectively preventing damage to important nerves. 2, cutting at the same time can close the blood vessels. 2.Cutting at the same time can be closed blood vessels, significantly reduce bleeding, shorten the operation time. 3.Reduced wound exudation, less drainage fluid after operation, and shorter retention time of drainage tablets. 4.No current passes through the body, does not interfere with the work of the pacemaker and other electronic components, more secure.