The principle of laser spot removal is through the selective photothermal principle, different wavelengths of light are absorbed by the corresponding pigment, pigment particles in the instantaneous absorption of the high energy of the laser rapidly expand, rupture, and form smaller fragments, which are cleared by phagocytes in the body in the ensuing inflammatory reaction. Thus, the purpose of lightening pigmentation is achieved. At the same time, the photothermal effect of laser can activate the skin fibroblasts, increase the expression of collagen, make the dermal collagen fibers and elastic fibers produce changes in molecular structure, increase in number, rearrangement, and restore the elasticity of the skin, so as to achieve the effect of reducing wrinkles, shrinking the pores, and making it tighter and more elastic. So the effect of laser spot removal is very good. Common spots are generally melasma, freckles and nevus of Ota, doctors will treat different types of spots with different energies and wavelengths. 1. Melasma: Q-switched large spot low-energy lasers and intense pulsed light, adjusting the appropriate wavelengths and energies according to the different shades of light. 2. Freckles: Currently, the commonly used treatments include Q-switched ruby laser with wavelength of 694nm, emerald green gemstone laser with wavelength of 755nm or intense pulsed light treatment. 3, Nevus of Ota: commonly used treatments include Q-switched ruby laser with a wavelength of 694nm, emerald green gem laser with a wavelength of 755nm and garnet laser with a wavelength of 1064nm. During the treatment period, you must do a good job of sun protection, do not let the sun damage to destroy the appearance of the skin. It is recommended to see a professional dermatologist when pigmentation occurs, who will use different instruments and determine the number of treatments depending on the type of pigmentation.