The invention relates to a process for making buckwheat grains. A preparation method of the process comprises the following steps: a, grinding buckwheat for later use, wherein buckwheat bran is for other use; b, grinding barley for later use, wherein wheat bran is for other use; c, grinding rice for later use; d, cutting tartary buckwheat into segments, and performing supercritical extraction to obtain a tartary buckwheat extraction concentrated solution for later use; e, pulping white fungus, and cooking the pulped white fungus into thick paste for later use; f, mixing buckwheat bran with barley bran, and extracting a bran mixture for later use; g, mixing buckwheat powder, barley powder, rice powder, the tartary buckwheat extraction concentrated solution, the white fungus thick paste and the bran mixture, feeding the mixture into a stirrer for stirring uniformly into a comprehensive material, making rice-shaped particles through a puffing extruder and a die, drying and packaging to obtain the buckwheat grains.