Ultrasonic lipolysis is to emulsify or shock the fat through ultrasonic waves to enhance the suction of fat, with less intraoperative bleeding, which can effectively reduce the doctor’s work intensity, and it is widely used in the clinic. The possible risks of ultrasonic lipolysis for arm slimming are as follows: 1) unevenness and uneven symmetry bilaterally; 2) delayed healing of liposuction incision: mostly caused by prolonged friction between liposuction tubes and the skin of liposuction incision, which can be avoided in early stage by constructing the tissue of liposuction incision and then suture it; 3) accumulation of fluid and subcutaneous ecchymosis: related to the lack of placing drainage tubes in the early stage and insufficient compression in the postoperative period. If the effusion is small, it can be absorbed by itself; if the amount is large, puncture can be performed and localized pressure bandage can be applied after suction. Ecchymosis can be treated without special treatment, and can subside in about 3-4 weeks, and can be supplemented with hot compresses and physiotherapy after 1 week to promote absorption; 4. Intra-operative and post-operative pain: related to uneven anesthesia, individual differences, loose bandage and not wearing tight clothes and pants after surgery, and appropriate oral painkillers can be taken after the surgery; 5. Post-operative subcutaneous nodules: those with little subcutaneous remaining fat are prone to formation of nodules and can be treated with medicines to activate blood circulation and remove blood stasis and with hot compresses and physiotherapy to aid in absorption. assist absorption. 6, infection: if the operator is not strictly sterilized during the operation, it is likely to lead to infection of the candidate, and need to take antibiotic treatment; 7, if the operator is not operating properly, it may lead to nerve damage in the operation area, resulting in some of the candidate’s sensory and motor dysfunction; 8, after the recovery of the operation, it may lead to skin hyperpigmentation. Patients are advised to avoid strenuous exercise for 1 month and have a reasonable diet that is both nutritious and moderate in intake.