The invention provides a highland barley and tartary buckwheat tea which comprises the flowing materials by weight parts: 20-60 parts of highland barley bran powder, 40-80 parts of tartary buckwheat seed endotesta powder, 1.5-2.5 parts of guar gum and 0.5-1.5 parts of endotesta. The preparation method comprises the steps: adding drinking water accounting for 30-60 percent of the total weight of powder in a mixture of the guar gum and gellan gum dry powder to prepare a binding agent, adding the binding agent in a mixed powder body of the highland barley bran powder and the tartary buckwheat seed endotesta powder, uniformly stirring to prepare dough, and standing the dough until fermenting; pelleting and forming the fermented dough; baking pelleted and formed granules at a temperature of 60-70 DEG C until setting, then baking at a temperature of 80-90 DEG C until drying, and naturally cooling to a room temperature; frying the baked and dried granules at a temperature of 110-130 DEG C until the water content is 4-7 percent to obtain the highland barley and tartary buckwheat tea. The highland barley and tartary buckwheat tea provided by the invention has the good functions of getting purge, regulating blood sugar, degrading cholesterol, enhancing immunity, expanding coronary arteries, and reducing the brittleness of blood vessels, and is remarkable in nutritive values and health care function.