Photochromic materials are functional dyes that can change color under the irradiation of ultraviolet or visible light, and can be reversed back to their original color after the light disappears. Photosensitive color changing materials mainly include silver chloride, silver bromide, stilbenes, spirocyclic compounds, norbornadienes, arginine anhydrides, triphenylmethane derivatives, salicylic acid aniline compounds, etc. At present, photochromic materials have developed to four basic colors: purple, yellow, blue, and red. The initial structure of these four photorefractive materials is a closed loop type, meaning that they are printed on the fabric without color, and only turn purple, yellow, blue, or red under ultraviolet radiation. Photochromic materials have the advantages of high resolution, direct imaging, and repeated use, as well as sufficient thermal stability, photostability, photochromic fatigue, and color sensitivity.