The injectable filler, whose main component is levopolylactic acid, can be used for filling and shaping sagging areas of the skin, as well as for the correction of fat atrophy caused by disease. It is an artificial substance, but it is compatible with the human body and can be decomposed and absorbed, with good biocompatibility and degradability. Its principle of action is to stimulate its own collagen growth to achieve anti-aging and tightening and lifting effect. However, caution should be exercised when using it, as with other injectable materials, there are some adverse reactions after injection, such as redness, swelling and pain at the injection site. In addition, if the injections are not done properly, they can cause complications such as bruising, contusions, edema, allergies, nodules, and infections. Precise injection is the most important factor to avoid complications, and improper operation may lead to embolism, skin necrosis, etc. Therefore, patients are advised to go to a regular medical institution for consultation, including preoperative communication with the doctor to understand the specific process of child injections, related risks, preoperative design, etc., and be psychologically prepared. Secondly, it is necessary to improve the physical examination, heart and lung, blood and other routine examinations to confirm that there are no serious systemic diseases and no allergy to levopolylactic acid or anesthetic drugs before the procedure is performed.