Scar is formed by the healing of the body after trauma, such as burns, trauma, abrasions, etc., showing unique appearance and pathological changes. The process of wound healing is accompanied by the generation of scars. Scar hyperplasia can have serious adverse effects on appearance and function, especially the scars formed after burns, scalds and severe trauma, which will bring huge physical and mental pain to patients. Hyaluronic acid is a kind of biological macromolecules, which plays a variety of roles in mediating tissue repair process. It is involved in three stages of wound healing : inflammatory activation, granulation formation and re-epithelialization. In recent years, hyaluronic acid has been widely used in clinical practice as a new method to prevent and treat scars. This article reviews the mechanism and clinical application of hyaluronic acid in the prevention and treatment of scars, in order to provide some reference for related clinical work.