Acne is a common dermatological condition that occurs as a chronic inflammatory disease of the sebaceous glands of hair follicles. It is most common in adolescent men and women and manifests itself as follicular papules, pimples, pustules, nodules and cysts on the face, forehead and back. As people age, most acne can heal on its own after the age of 25, so some people do not take acne seriously and consider it a minor problem. While mild acne can be controlled with topical medications, moderate to severe acne requires timely treatment to avoid scarring, hyperpigmentation, and even disfigurement after healing. Acne has a complex etiology and is a multifactorial disease. The pathogenesis includes excessive secretion of sebaceous glands due to androgens, abnormal keratinization of sebaceous ducts in hair follicles, microbial infections, and abnormal inflammatory reactions. Therefore, treatment is often directed at the above pathogenesis. Photodynamic therapy developed in recent years has achieved better results in the treatment of acne. Photodynamic can destroy part of the sebaceous glands, reduce sebum secretion, and also kill Propionibacterium acnes, as well as have anti-inflammatory and promote repair effects, with small adverse reactions and no adverse effects on the system, and is especially suitable for the treatment of moderate to severe acne. effectively control the progress of the disease.