The invention relates to application of a snow tea extract to preparation of a medicine for preventing and treating zymloid protein diseases. The influence on zymloid protein fiber formation by the snow tea extract is mainly explored, a new effective treatment medicine for preventing and treating zymloid deposition diseases is expected to find, and support is provided for medicinal research on thesnow tea. Typical zymloid protein chicken lysozyme is mainly subjected to in-vitro culture to form fiber and secreted protein of a recombinant pichia pastoris strain of chicken cystatin forms fiber.The result indicates that the snow tea extract achieves the effect of inhibiting the zymloid protein from forming the fiber; furthermore, in the water extract group, the effect is more significant andthe IC50 value is about 0.018 mg/mL. The bacterial level protein expression experiment indicates that the snow tea extract can inhibit a chicken cystatin zymloid mutant I66Q from forming aggregate extracellularly in a concentration dependency way; and when the extract concentration reaches to 1.5 mg/mL, a certain inhibition effect can be generated on oligomerization and aggregation of the secreted protein.