In some severe acne patients, visible marks often appear after the acne subsides: red, brown, and depressed, all of which can cause trouble. So, how do you remove these acne marks? Patients with acne can consider removing acne marks after proper treatment and the rash has been stable for about 3 months. Optical treatment is generally recommended; commonly used are photorejuvenation, fractional laser, radiofrequency, photodynamic therapy, etc. Photorejuvenation can remove capillary dilation, hyperpigmentation, and depressed scarring without vacation and recovery period, without affecting work, with slower results, usually requiring 5~6 or more treatments. Fractional laser and radiofrequency treatment will have slight peeling and crusting, with a recovery period of 5~7 days; depending on the severity of the condition usually requires 5 treatments. Fractional laser works by applying tiny laser beams to the skin, creating many evenly spaced micro-zones of damage, increasing collagen synthesis, allowing dermal remodeling, improving superficial scarring, reducing pores, and removing discoloration. Due to the presence of normal skin tissues around the damaged area, it promotes tissue healing and accelerates repair. Photodynamic therapy is a new disease treatment based on the interaction of light, photosensitizer and oxygen. The photosensitizer can dynamically concentrate in the tissue with abnormal growth, and it can generate reactive oxygen substances such as singlet oxygen by photodynamic reaction under the excitation of appropriate wavelength light, while destroying the target cells. It directly kills pathogenic microorganisms through photochemical reactions; directly acts on the sebaceous glands, permanently inhibits sebum secretion, anti-inflammatory repair, prevents scar formation, and promotes tissue repair. Good safety and quick effect.