Photorejuvenation means that the skin is irradiated with continuous intense pulsed light at low energy to improve the skin condition and repair skin damage, etc.. However, there are still certain risks and disadvantages of such technology, including the possibility of temporary blistering or even edema due to improper use of energy, so it is recommended to go to a professional hospital for treatment: I. Advantages: this technology has less side effects, non-invasive operation, fast recovery, and does not affect daily life and work. 1. Short-wave light: it can selectively act on subcutaneous capillaries, pigmentation, scarring, etc. to narrow capillaries The technology can be used to eliminate the presence of erythema and pigmentation; 2. Long-wave light: stimulate the generation of collagen and elastic fibers, enhance skin elasticity, and improve skin dullness and wrinkles, etc. Second, the disadvantages: the effect of the technology to maintain a short period of time, there is a need for those in need of treatment again. 1, erythema, blister: can be due to high pulse light energy, or due to uneven application of light guide gel between the treatment handpiece and the skin, resulting in burns on the skin, causing erythema or blister; 2, pigmentation decompensation: can be due to improper setting of pulse light energy, causing darker skin or long-term sun exposure people pigmentation decompensation, or even pigment loss. In addition, some people experience temporary redness, burning, and pain after photorejuvenation treatment, which is a normal phenomenon and can be relieved by cold compresses and following medical advice for follow-up skin care, which can relieve symptoms in the short term.