Cold light tooth whitening technology is to transmit high-intensity blue light with wavelength between 480-520 nm through optical fiber, pass through two special optical lenses with 30 layers of coating, and then undergo special optical treatment to remove all harmful ultraviolet rays and infrared rays, so that the whitening agent with hydrogen peroxide and silica with diameter of 20 nm can quickly produce redox effect. Remove the pigment attached to the surface and deep layer of teeth through the tooth tubule, so as to achieve the effect of whitening.