The invention belongs to the technical field of wool fabric industry, and particularly relates to a yak hair denaturation and color-fading method. The yak hair denaturation and color fading method comprises the following procedures: denaturation and color-fading, washing with warm water, reduction and washing, washing with hot water, and oxidization bleaching sequentially. By adopting chemical denaturation treatment, a part of hydrogen bonds and disulfide bonds in the yak hair fiber are broken, then disulfide bonds are rebonded at new positions, therefore, the disulfide bonds are decreased compared with those of raw hair, hair is supercontracted, curling is generated on the appearance, fiber is soft and rich in elasticity; by utilizing the affinity difference between yak hair fiber pigment and keratoprotein, ferrous ions are mordanted on pigment-containing parts of yak hair in advance, ferrous ions are washed from the parts without pigment on the yak hair with hot water alternatively, excessive free radical oxygen is removed by utilizing catalase so as to benefit the dyeing of the dyeing procedure, the application range of yak hair is widened, and the new yak hair textile product is developed.