If left untreated, this kind of birthmark will thicken and darken as the child grows older, and even pimples will grow on it, so it must be found and treated early. The traditional treatment methods for nevus are ineffective and easy to leave scars, currently the better method is to use laser, light therapy and photodynamic therapy. 1.Variable pulse width multiplier 532 nm Nd:YAG laser The yellow light emitted from it is absorbed by oxygenated hemoglobin in the blood vessels, which in turn generates heat and causes thermal damage to the blood vessels to achieve the treatment purpose, this principle is called the principle of selective photothermal action. Because there are various pulse widths, it can effectively and gently heat various different diameter of the deformed blood vessels, the treatment range is wide; and equipped with synchronous cooling device, obviously reduce the pain, most patients have obvious effect after multiple laser treatment. 2.Intense pulsed light (IPL) treatment is a mixture of light with wavelengths from 400 to 1 200 nm, and the treatment still abides by the principle of selective photothermal action. It has better effect on smooth or superficial bright red nevus and vascular dilatation. IPL is an optional method when other laser treatments are ineffective or when smaller purpura reactions are expected to be treated. 3.CO2 laser For thicker or superficial lumpy vivid nevus can be used together with CO2 laser, which is an effective method to improve vivid nevus in a comprehensive way. 4.Photodynamic therapy is a new treatment method which has obvious treatment advantages for patients with larger and thicker erythema nodosum. The treatment principle is that after the photosensitizer is injected into the human body through the vein, it will mainly gather in the parts where the erythema nodosum is distributed, and a large amount of active oxygen will be produced under the light irradiation of specific wavelength, which can lead to the necrosis of the proliferated blood vessels, and then the necrotic blood vessels will be removed by the organism to achieve the treatment purpose. After this method of treatment, the regression of nevus is more even, the number of treatments is less, and the efficacy is safe and reliable. Since each patient’s condition is different, the choice of treatment plan for nevus of vivid redness should be based on a comprehensive assessment of the patient’s condition, and different optimal treatment methods should be chosen for different patients.