The invention relates to the technical field of food and in particular relates to buckwheat tea which has a synergism effect and a function of improving the taste. The buckwheat tea is prepared from the following raw materials in percentage by weight: buckwheat, fructus lycii, semen cassiae, chrysanthemum and green tea according to the ratio of 3:1:1:1:1. A preparation technology comprises the steps of cleaning the buckwheat, steaming the buckwheat until the buckwheat is thoroughly cooked, taking out the buckwheat, and drying, smashing and screening the buckwheat for later use; feeding the fructus lycii, the semen cassiae, the chrysanthemum and the green tea into a decocting pot according to the amounts in the formula, respectively performing water extraction twice, filtering, combining two extracting solutions, and concentrating the combination to obtain clear paste; mixing the clear paste with the buckwheat powder, and performing granulation, drying, frying, dividing and packaging to obtain the buckwheat tea. The buckwheat tea, which is prepared according to the formula and the preparation technology which are disclosed by the invention, achieves a main health-protection effect through the nutritional and active components of the buckwheat; the other four traditional Chinese medicines with homology of medicine and food can achieve synergism on the buckwheat; by virtue of the united effect, the buckwheat tea achieves the effects of reducing the three highs, nourishing and activating the blood, protecting the liver, improving the eyesight and loosening bowel to relieve constipation.