From the perspective of LED light strip emission, LED lights are made by encapsulating GaN chips and yttrium aluminum garnet (YAG) together. The GaN chip emits blue light (λ p=465nm, Wd=30nm), and the YAG fluorescent powder containing Ce3 sintered at high temperature is excited by this blue light and emits yellow light with a peak of 550nm. The blue LED substrate is installed in a bowl shaped reflective cavity and covered with a thin layer of resin mixed with YAG, about 200-500nm. Part of the blue light emitted by the LED substrate is absorbed by the fluorescent powder, and another part of the blue light is mixed with the yellow light emitted by the fluorescent powder to obtain white light. Now, for InGaN/YAG white LED lights, by changing the chemical composition of YAG phosphor and adjusting the thickness of the phosphor layer, various colors of white light with a color temperature of 3500-10000K can be obtained. This method of obtaining white light through blue LED lights is widely used due to its simple construction, low cost, and high technological maturity. This is one of the principles by which LED light strips emit light.