Photorejuvenation is the application of specific intense pulsed light, directly irradiated on the surface of the skin, which can penetrate to the deeper layers of the skin, selective action on the skin pigment or blood vessels, destroying pigmentation, closing the abnormal red blood filaments, can be effective in the treatment of the skin surface imperfections, improve skin elasticity, color and fineness, and maximize the satisfaction of consumers on the pursuit of high-quality image. However, photorejuvenation also has the following side effects: 1, burns the skin: in photorejuvenation treatment, if the photon energy is too large, it will burn the skin, and play a counterproductive effect; 2, skin sensitivity: after photorejuvenation treatment, the skin of the lovers is prone to become abnormally sensitive, itchy, red, swollen, peeling, etc.; 3, melanin deposits: incorrect photorejuvenation treatment is likely to lead to damage to the skin cells The skin is unable to repair and protect itself, which will lead to the precipitation of melanin on the face and the aggravation of pigmentation; 4. Damage to the stratum corneum: when the stratum corneum of human skin is damaged, the skin will lose its protective barrier, and the loss of nutrients will be accelerated, so the skin condition will be imbalanced and the aging will be accelerated; 5. Post-operative rebound: there are certain risks in photorejuvenation, for example, rebound phenomenon occurs after the elimination of spots, and the area of the pigmented spots will be bigger than the original one. In addition, after photorejuvenation, due to a series of reasons such as strong stimulation of the skin, accelerated skin metabolism, elevated local temperature of the skin and weakened protective function of the sebaceous membrane, it will lead to dehydration and dryness of the skin. Therefore, a lot of water must be added to soothe and calm the skin after the treatment. In addition, the effect produced by photorejuvenation is gradual, and often can not be harvested once the amazing results, therefore, photorejuvenation must be treated in accordance with the course of treatment.