Ultrasonic lipolysis for thigh slimming is a non-invasive treatment, based on the principle of ultrasonic emission outside the body and focusing inside the body, the ultrasonic waves will irradiate the human leg fat tissues at a fixed point, and through the mechanical and thermal effects of its destroying the fat cell membranes, the use of excessive swelling liquid will make the fat cells rupture and dissolve, and the number of leg fat cells will be reduced in a lasting way, so as to realize the long-lasting leg shaping effect. Although this method can achieve the effect of leg slimming, it also generates certain risks, such as slight edema, ecchymosis and dullness of tactile sensation inevitably exist in most patients after the surgery. However, the edema and ecchymosis may subside within 2-4 weeks, and the slight dullness of touch usually subsides within 1-2 weeks. Some people may also experience temporary redness, ecchymosis, and other discomfort in the operated area, which usually subsides within a few days. The risks also include localized skin damage, which can be caused by scarring or improper handling. It is recommended that patients choose a regular plastic surgery institution for medical treatment and standardized surgical operation, which can effectively prevent the occurrence of complications. In addition to this, it is important to communicate with the doctor before the operation to understand the specific process of the project, the risks associated with it, the preoperative design, etc., and to be psychologically prepared. Secondly, it is necessary to improve the physical examination, cardiopulmonary, blood and other routine checks to confirm that there is no serious systemic disease, and to confirm that there is no allergy to anesthetic drugs before proceeding. Good postoperative care in accordance with medical advice is also conducive to preventing complications.