Skin aging can be divided into natural aging and photoaging according to different causes. Natural aging of the skin is mainly caused by endogenous factors of the body, such as straightening and structural loosening of dermal collagen fibers, progressive degradation and thinning of elastic fibers, and shortening of anchor fibers, which are clinically manifested as skin laxity, wrinkles, dryness, flaking, increased brittleness, and poor repair function. Skin photoaging is due to the massive reduction of procollagen and precollagen produced by long-term sunlight cumulative exposure, loss of skin support structure, and ultrastructural disorder of collagen fiber bundles, significant decrease in skin elasticity, progressive degeneration of elastic fibers, hyperplasia, thickening, curling, formation of thickly dyed clump-like aggregates, almost disappearance of anchor fibers, and consequent loss of skin elasticity and compliance. The clinical features are: wrinkles, sagging and roughness, enlarged pores, hyperpigmentation, freckle-like nevus, capillary dilation, pseudoscarring, precancerous lesions and malignant tumors, etc. Photorejuvenation is based on the principle of selective photothermal absorption, using specific intense pulsed light energy to penetrate the skin, and the specific multi-band light waves released after irradiating skin cells can rapidly enhance the repair and regeneration ability of skin cells, while promoting the reorganization of collagen and elastic fibers, completely eliminating or reducing pigment particles, improving red blood filaments, shrinking capillaries and wrinkles, safely, effectively and conveniently getting rid of skin surface It also improves skin elasticity, color and delicacy, and restores the vitality of young skin. The pressure brought by the fast-paced life of the modern city and the bad emotional environmental pollution can seriously damage the natural moisture balance of the skin and weaken the self-protection of the skin, thus disturbing the healthy balance of the skin and causing problems such as dehydration, dullness and dry lines.