Intense pulsed light (IPL) is a broad-spectrum light formed by focusing and filtering a very high intensity light source, which is essentially a non-coherent ordinary light rather than a laser. The difference between intense light and laser is that intense light is a group of relatively concentrated wavelength, adjustable pulse width, non-coherent high-energy light. Since the introduction of the first generation of intense light devices in 1994, the technology of intense light has been constantly updated, and the wavelengths of intense light used for treatment have evolved from the initial visible light to ultraviolet, blue and infrared light, allowing for the expansion of its clinical indications. The commonly used photon technologies are photorejuvenation (560, 570, 590, 640nm), blue light technology (420nm), and infrared light technology (Titan technology, NIR technology, ST technology). Clinical indications for intense pulsed light (IPL) include skin photoaging (fine wrinkles, enlarged pores, skin laxity, uneven pigmentation), superficial pigmented dermatoses (freckles, age spots, coffee spots), capillary dilation (normal skin, sensitive skin), sensitive dermatoses, acne (inflammatory acne, post-acne erythema, acne), rosacea, hirsutism, vitiligo, psoriasis. Photorejuvenation technology is a non-ablative power therapy that uses continuous intense pulsed light (IPL) at low energy density for non-ablative, non-invasive skin rejuvenation treatments. Intense pulsed light emits a spectral range of 560 to 1200 nm. Its longer wavelengths can improve photodamage and aging phenomena of the skin, while shorter wavelengths can treat pigmented and vascular lesions of the skin. The skin changes of photoaging are usually formed by the increase of skin pigmentation spots, capillary dilation and skin texture changes. In order to obtain satisfactory results for photoaging treatment, it is not ideal to treat any one of the skin problems alone, but only to solve all three skin problems at the same time to obtain the so-called “skin rejuvenation” effect. Since IPL is a kind of “compound light” and has a long pulse width, it is very advantageous in terms of the comprehensive effect of skin rejuvenation, and all three kinds of skin damage can be achieved to a certain extent after IPL treatment, including the reduction or elimination of pigment spots, improvement or elimination of capillary dilation, smoothness of the skin, cleanliness of the skin, and reduction of fine wrinkles. These include the reduction or elimination of pigmentation, improvement or elimination of capillary dilation, skin smoothing, elimination of fine wrinkles, and slight skin tightening. This effect can only be obtained after a series of multiple treatments, which is called a course of treatment. To achieve more desirable results, one treatment every 3 to 4 weeks and 4 to 6 consecutive treatments are very necessary. Compared to traditional peels such as mechanical grinding, chemical peeling and laser treatment, photon technology has 4 major advantages. 1. non-invasive skin rejuvenation technology. 2. multiple skin problems can be improved simultaneously in a single session. It can effectively remove or diminish various pigment spots and age spots; remove facial capillary dilation and erythema rosacea; reduce fine wrinkles; shrink large pores; significantly improve facial skin roughness; reduce mild acne scarring; effectively improve skin texture and elasticity, making facial skin smooth, delicate and elastic; and also remove unwanted facial hair.3. Comprehensive treatment. It is a breakthrough from the limitations of lesion treatment in the past, so that the cosmetic effect can reach every part of the body. 4. No need for vacation. After the treatment, there is only slight edema, redness and no other discomfort, and the treatment can be put into normal work and life without rest. The mechanism of action of intense pulsed light (IPL), including: 1, selective photothermolysis: specific broad spectrum of intense pulsed light can penetrate the skin and be preferentially absorbed by melanin in the skin and hemoglobin in the blood, without damaging the normal skin, so that vascular coagulation, pigment clusters or pigment cells destruction, decomposition, so as to achieve the effect of treatment of capillary dilation, pigment spots. 2, photothermal effect. Increases collagen and promotes collagen regeneration. 3. Inflammatory infiltration in the superficial dermis subsides, and melanophagy appears in the dermal papillae. Intense pulsed light (IPL) treatment before thoroughly cleaning the surgical area, removing skin oils and cosmetics. A cold gel is applied to the treatment area, and the appropriate treatment parameters are selected according to the patient’s skin and lesion conditions. After IPL treatment, you can wash your face and put on makeup. Side effects and complications are rare after IPL treatment, but different treatment parameters should be used for different patients and different treatment stages of the same patient during the treatment. After treatment, measures such as sunshades and sunscreen can be used to avoid sun exposure for more than 10 to 14 days.