Laser scar removal uses different wavelengths of colored light to selectively treat the scar area. By controlling the wavelength of the laser, it can repair scars of different tissues and degrees without harming the skin tissue. When the laser light is applied to the skin, it penetrates into the subcutaneous area and turns the scar tissue from particles to powder until it is absorbed by the cells and cleared, and the scar then changes from deep to light and from light to nothing. Although laser scar removal is effective, there may be some side effects such as erythema, which usually lasts 6-10 weeks and fades on its own. Secondly, if the dermal layer of the subcutaneous tissue is irritated, it is very easy to form scar growth. In addition, this can also happen if the patient takes collagen supplements at will. This is because the laser can damage the subcutaneous tissues and cause collagen growth, and additional collagen supplementation can cause excess collagen in the body, which can cause scar tissue growth. In addition, if the laser is excessive, it may cause pigment loss, and if the sebaceous ducts are temporarily blocked, a milia may appear. In the case of cellular changes, cellular necrosis may also occur. Infection may also occur, usually related to irregular aseptic operation, improper daily care exposure, and low personal resistance of the candidate. If any of these adverse reactions occur, it is recommended to visit a hospital for examination and take appropriate measures to deal with them.