According to the yellow
leuco dye developing ink and the preparation method thereof disclosed by the invention, by optimizing the molecular structure of the yellow
leuco dye and the matching relationship between the yellow
leuco dye and a color developing agent, the ink can quickly develop under the conditions of low temperature, slight pressure or low-concentration acid /
metal salt, the developing effect is distinct, and
handwriting or patterns are clear and visible; by selecting a yellow leuco dye with better photostability of a color body after color development and introducing an
antioxidant component, the color
fading of a color development product under the
irradiation of
ultraviolet and visible light is effectively delayed, and the storage period of color development images and texts is prolonged; by improving an ink formula and a packaging process, the ink can keep good leuco stability in different environments such as high temperature,
high humidity, low temperature and the like, and the phenomena of self color development, non-uniform color development and the like are prevented. The ink is colorless or light in color under
normal conditions, can show bright yellow after being stimulated by acid,
metal salt or heat, and has the characteristics of
high color developing sensitivity, clean background and wide application range, and the comprehensive performance of the ink is remarkably improved.