Poly-L-lactic acid (PLLA) is a new type of biodegradable polymer material,which has been widely used in the medical field in recent years, such as absorbable sutures, bone repair materials, soft tissue repair scaffolds and so on. In addition, PLLA can also be used for filling injection, improving and reconstructing skin, resisting aging, and promoting tissue regeneration and repair,which is the main method for clinical application in facial rejuvenation. This article will review the chemical and biological characteristics of PLLA, the needs of facial rejuvenation, and the mechanism and application of PLLA in facial filling injection, in order to clarify the application prospect of PLLA in facial rejuvenation, as well as provide strong support for the development and innovation of medical cosmetology.