Poly- L-lactic acid is a biodegradable polymer material with good biocompatibility. In recent years, it has high application value in the medical industry. Because of its non-toxic, non-irritating and high plasticity, it is widely used in the field of medical beauty. Therefore, this article reviews the mechanism of action, use methods, current application status and prospects of poly-L-lactic acid on skin tightening by consulting and sorting out relevant literature, in order to clarify the application of PolyL-lactic in skin tightening, aiming to provide reference for the clinical application of poly-L-lactic acid in skin tightening.