Autologous fat breast augmentation is an operation to extract fat from one’s thighs or abdomen, and after special purification treatment, inject the fat into the various levels of the breast with a syringe to increase the volume of the breast. The volume of one injection of autologous fat breast augmentation surgery is generally 150-300 ml per side, and local massage makes the fat distribution evenly to achieve the ideal shaping effect. Depending on the patient’s requirements, 2-3 injections are usually performed to achieve the final required breast volume size and shape. The side effects of autologous fat breast augmentation mainly include the following points: 1. The injected fat is susceptible to infection and liquefaction and necrosis, so the sterile condition of the operating room and the disinfection of the operation should be higher. The operation needs strict attention to aseptic operation in order to ensure the success of the operation. Therefore, it is important to choose regular and qualified professional hospitals and institutions to perform the surgery. 2. Complications such as fat hardening and liquefaction may occur after the surgery, and fat concentration in the same area should be avoided. There should not be too much fat injected at each time to reduce the consumption of metabolism and improve the survival rate; 3. If the fat is injected into the blood vessels by mistake, it can cause fat embolism. In mild cases, it can cause local skin darkening and hardening, and pain. In severe cases, it can lead to blindness, and even cause pulmonary embolism, cerebral infarction, etc., which is life-threatening.