The five fields defined by the North American Laser Therapy Society for low-power light sources have actually been used in clinical practice by a small number of physicians in China. Such as low-level lasers are used in segmented vitiligo; narrow-band irradiation, such as light-emitting diodes for rejuvenation; broad-band irradiation, such as red and blue light, for acne control; photodynamic therapy for cancer treatment , and some doctors use it to remove acne; polarized light therapy, using a special polarizer, makes the emitted light become parallel light with better penetration, and achieves the effect of skin beautification with a wide-band spectrum. Clinically used to improve acne scars, enlarged pores, epidermal spots, fine wrinkles and increase skin firmness. It is also currently the most used treatment method for individuals, and consumer satisfaction is very high.