Chloasma usually occurs on the patient's face, and it is a skin disease with excessive melanin, which will be aggravated under strong light. The pathogenesis is also very complicated. Generally speaking, it is related to the following factors, such as genetic factors, ultraviolet radiation, pregnancy, oral contraceptives, nutritional factors, ovarian diseases, increased estrogen and progesterone levels, skin microecological imbalance, hormone therapy, tyrosine dysfunction, abnormal serum copper content, decreased anti-free radical function, endocrine disorders and so on. The method of removing chloasma with carrot juice: crush fresh carrots and juice, and take 10 ~ 30ml. After washing your face every morning and evening, pat your face with freshly squeezed juice, and then pat your face with your hand coated with vegetable oil when it is dry. In addition, drinking a glass of carrot juice every day also has the effect of removing spots, because carrots are rich in vitamin A, which can lubricate and strengthen the skin and prevent rough skin and chloasma. "Nano-wave comprehensive therapy" carried out by the Research and Treatment Center of Chloasma, Institute of Dermatology, China Academy of Sciences is a broad-spectrum non-invasive photodynamic therapy, which can scientifically and efficiently remove chloasma. At the same time, experts from the research and treatment center of chloasma of the Institute of Dermatology, China Academy of Sciences also cooperated with Chinese medicine. According to the fact that chloasma is caused by the dysfunction of liver, spleen and kidney, comprehensive conditioning from the inside out, combined with nano-wave irradiation, can achieve the effect of freckle removal and whitening in a short time, which is the most advanced and scientific technology to remove chloasma at present. Academia Dermatology Institute has three advantages in treating chloasma: 1, leaving no scar and no damage to skin; because a certain wavelength of nano-wave can only be absorbed by the pigment of the corresponding color, only diseased cells can absorb the specific nano-wave, and nano-wave technology can also control the depth of light wave reaching the skin.