The invention discloses a processing method of a hair blackening tea, wherein folium mori and old-tree purple tea are both obtained through material section, wilting, the deactivation of enzymes, rolling, sun-drying and fermentation; the fermented folium mori and old-tree purple tea are mixed and matched according to a proportion, in percentages by weight of 70 to 80 percent of the folium mori and 20 to 30 percent of the old-tree purple tea, and then are aired, so that the hair blackening tea is obtained. The hair blackening tea provided by the invention has the functions of the folium mori and the old-tree purple tea at the same time, can realize mutual promotion of the folium mori and the old-tree purple tea, has the functions of hairdressing, retaining youthful looks, being anti-aging and being capable of blackening white hair and restraining the white hair from growing, and in addition, also has the effects of removing heat from the liver, improving eyesight, enhancing vascular elasticity, preventing cardiovascular and cerebrovascular diseases, protecting the liver, improving a circulatory system, increasing the smoothness of a skin, restraining an inflammation and an allergy, improving the flexibility of a joint, being anti-coagulation, lowering blood pressure, reducing blood sugar, reducing blood fat and reducing cholesterol.