The popularity of photothermal therapy has allowed beauty lovers to enjoy the convenience of cosmetic treatments. Beauty seekers also need to know more about photothermal energy when they demand more professional, safer and healthier solutions. First of all, low-energy illumination should not be confused with high-intensity light such as laser and pulsed light. Low-energy light, like the “optimization” of the Internet, is a plus in a well-designed overall beauty treatment, from the most basic cleansing to the deeper repair, where light and the use of maintenance products complement each other. Low-Level LaserTherapy (LlT) was first introduced by Professor EndreMester of Semmelweis University in Hungary in 1967 and is now used in many fields. It can be used by dermatologists to effectively combat acne, in medicine and surgery to accelerate wound healing, and in professional athletics to relieve exercise-induced muscle fatigue and improve muscle endurance. Low-energy power light, giving the epidermis a gentle and harmless energy. There are various kinds of photothermal therapy on the market, “color light”, “skin softening light”, “beauty light”, “white snow light”, etc. It is a very beautiful term, basically using the thermal principle of light, and its official name is “PhotodynamicTherapy” (PDT). PhotodynamicTherapy is a kind of low energy, high brightness, safe and stable dipolar light (LED), which is a special nano-level wavelength light separated from the sunlight, and is a single frequency light that can penetrate deep into the bottom layer of the skin. Scientific research has proved that the wavelength of photodynamic can stimulate cell growth and make it 5 times faster than normal, which works well for wound treatment and repair, and is also effective for acne wounds and maintenance products introduction, but it must not be used for whitening and spot removal. At present, there are four kinds of photodynamic power mainly used in the field of beauty: blue light, green light, yellow light and red light. Blue light: wavelength 415nm, used to improve pore size, treatment of acne, acne, balancing oil soothing and calming effect. Green light: wavelength 525nm. used to improve skin tone and treat skin dullness. It can also repair sagging skin and acne. Yellow light: wavelength 590nm. accelerates wound healing and enhances the absorption of maintenance products. Red light: wavelength 660nm, used to inhibit inflammation, improve fine lines and sensitive skin. Precautions: People whose skin is sensitive to light, those who are taking photosensitive medicine, and pregnant women are not allowed to use.