The invention discloses an in-bulk Tibet tea and a preparing method thereof. The preparing method includes the following steps that 1, tea leaves are selected in a flotation mode, aired in a spread mode and screened; 2, water removing is carried out; 3, fumigation is carried out; 4, rolling is carried out; 5, pile fermentation is carried out, wherein enzyme liquid with an enzyme activity keeping agent and a compound enzyme preparation is sprayed to the tea leaves for fermentation; 6, overturning and picking are carried out; 7, baking and airing are carried out. The Tibet tea prepared with the preparing method is convenient to carry and brew, is in auburnish black color, is bright and has the four unique characteristics of being red, thick, mellow and old. Tea soup is rosy, fresh and lovely; the tea is authentic in flavor, and is tasty, refreshing, merry and lively during drinking; the fragrance of the tea is thick; when entering the mouth, the tea soup is not puckery and bitter, smooth, sweet and mellow in taste. The Tibet tea prepared with the preparing method has the effects of resisting oxidation, reducing hyperlipidemia, hypertension and hyperglycemia, inhibiting arteriosclerosis, resisting radiation, mutation and viruses, coordinating the intestines and the stomach, improving metabolism, carrying out detoxifying, improving water quality and comprehensively supplementing microelements and vitamins.