Skin photoaging is the damage caused by long-term exposure to sunlight, manifested as wrinkles, dry skin, sagging, increased pigmentation, capillary dilation, and often grayish-yellow skin tone. Intense pulse light is a commonly used non-invasive treatment for photoaging, which can reverse the clinical manifestations of photoaging, so this treatment technology is called photorejuvenation in China. Intense pulse light (IPL) is composed of single pulse or multi-pulse sequence of non-coherent, high energy density light pulses with a wide spectral range of 500-1200nm, including visible light, i.e. seven colors and some infrared light, so it is also called intense light or color light. In clinical use, through the adjustment of parameters such as wavelength, pulse, pulse delay and spot energy, different treatment effects can be produced, which is currently recognized as a non-invasive technology with high safety and effectiveness in treating photoaging. The principle of skin rejuvenation by intense pulsed light is selective photothermal and photochemical action. The specific performance are: (1) the melanin in the skin as the color base that is the target tissue to absorb light and produce photothermal effect, “internal blast effect” or “selective pyrolysis”, so that the pigment cell groups such as destruction, decomposition, pigment fragments off or by phagocytes (2) hemoglobin with absorption peaks at 542nm and 577nm can absorb light energy and convert it into heat energy, thus causing denaturation and coagulation of hemoglobin and damage to capillary endothelial cells, eventually leading to degeneration of blood vessel occlusion; (3) collagen fibers in the skin partially absorb the light waves emitted by intense pulsed light, and part of the heat absorbed by other tissues in the skin can also be transmitted to the dermis, resulting in deep skin tissue This can produce photothermal and photochemical effects in the deeper skin tissues, causing a slight local inflammatory reaction, inducing a damage repair process in the fibers, and achieving fiber proliferation. Clinical application in (1) pigmented diseases pigmented skin diseases mainly include freckles, coffee spots, pigmented nevi, pigmentation, uneven skin color and other diseases caused by abnormal melanin in skin tissue. (2) Benign vascular skin lesions mainly include capillary dilation, hemangioma, bright red nevus, wine red nevus, etc. (3) hair removal (4) treatment of acne (5) treatment of rosacea (6) removal of wrinkles, skin rejuvenation, can effectively improve the skin roughness, uneven pigmentation, capillary dilation of photoaging symptoms.