Melasma is a common acquired hyperpigmented skin disease, which is a light brown or yellow-brown patch, symmetrically distributed on the cheeks, forehead, nose and bridge, sometimes in the shape of a butterfly, mostly on the face, mostly showing symmetrical pigmentation in the shape of butterfly wings, so it is also known as “butterfly spot” (pregnancy spot, liver spot). This disease is mostly seen in young and middle-aged women. It is aggravated by light in summer and reduced in winter. The surface is smooth and the edges are clear. It is generally believed to be related to endocrine hormone metabolism abnormalities. In addition, it is also related to drugs, cosmetics, sunlight, nutrition and micro-ecological dysregulation of skin lesions. Although chloasma is not painful or itchy, it affects the beauty and is a major “heart disease” for women who love beauty. Melasma lesions are confined to the exposed parts of the skin, often distributed on the face, mainly on the cheek, nose, forehead and chin, occasionally accompanied by hyperpigmentation of the areola and external genitalia. The lesions are usually light brown, gray, brownish gray, brownish black or even dark blue-gray patches of pigmentation fused together. They may vary in size and number and may form bow-shaped or multi-ring lesions, with a linear or comedogenic distribution, symmetrical occurrence and a butterfly-wing-like appearance. Most of the lesions have clear boundaries, and when the pigmentation is small, the edges may not be clear, but diffusely distributed. There is no scaling on the surface of melasma, no infiltration, and generally no other lesions such as erythema and papules. The development of the disease is slow, and the duration of the disease is difficult to determine, and may last for several months or years. Patients mostly have no self-conscious symptoms. At present, the more effective methods for treating melasma include laser, vitamin C introduction, Chinese medicine treatment, etc.