The cause of chloasma formation is unknown and may be related to genetic susceptibility, changes in endocrine levels, drugs such as phenytoin sodium, oral contraceptives, and systemic diseases such as liver disease. Ultraviolet radiation and poor quality cosmetics can induce this disease. The treatment of melasma needs to be based on the prevention of ultraviolet radiation and reasonable selection of topical drugs and oral drugs, and the common treatment methods are as follows: 1. Topical drug treatment: hydroquinone cream is the first-line drug for the treatment of melasma, the higher the concentration the stronger the decolorization effect, but the greater the stimulation to the skin. Azelaic acid cream and retinoic acid, used in combination with hydroquinone and steroid hormone topically can improve the efficacy. In addition, fruit acid also has the effect of auxiliary treatment of melasma, but it has certain irritation to the skin and may lead to pigmentation; 2. Systemic medication: Patients can take oral medication for treatment, such as vitamin C and vitamin E combined treatment, which has the effect of anti-lipid peroxidation and inhibiting melanin synthesis; 3. Photoelectric treatment: Melasma can be treated by picosecond, super picosecond laser and intense pulsed light.