Objective: The effect of superfine grinding on the physicochemical properties of tartary buckwheat powder in different parts was studied, aiming to provide a certain theoretical reference for the food industry to use superfine grinding to prepare tartary buckwheat food. Methods: Tartary buckwheat skin powder, core powder and whole powder were used as materials to prepare tartary buckwheat ultrafine powder by superfine grinding combined with a fluidized bed jet mill. The superfine powder was studied by measuring the particle size, specific surface area, comprehensive powder characteristics, swelling property, water solubility and other indicators. Results: The particle size of the three kinds of tartary buckwheat powder was reduced to 8.15, 8.43 and 8.04 μm, respectively, after micronization treatment, with the specific surface area increasing; the micronization treatment reduced the fluidity and filling property of the powder. The water solubility increased, while the swelling capacity, water holding capacity and oil holding capacity showed a trend of first increasing and then decreasing. Conclusion: Tartary buckwheat powder has relatively excellent physical and chemical properties after jet milling and can be used for deep-processing of tartary buckwheat products.