The invention belongs to the food processing field of staple food and relates to buckwheat steamed bread with a high flavone content and a preparation method of the buckwheat steamed bread. The buckwheat steamed bread is prepared from the following components: high gluten wheat flour, tartary buckwheat powder, sweet buckwheat powder, alpha-amylase, pentosanase, water and yeast. The preparation method of the buckwheat steamed bread comprises the following steps of: firstly, carrying out vacuum freeze drying and ultrafine grinding treatment on the tartary buckwheat powder and the sweet buckwheat powder, respectively; then, uniformly mixing the high gluten wheat flour, the tartary buckwheat powder, the sweet buckwheat powder, the alpha-amylase, the pentosanase and the yeast and then adding water to the mixture; and finally, mixing, tabletting, dividing and forming, fermenting, cooking, cooling and packaging to obtain the buckwheat steamed bread with the high flavone content. According to the buckwheat steamed bread with the high flavone content and the preparation method of the buckwheat steamed bread, the content of the favone in the buckwheat is improved, processing performances, such as elasticity and viscosity, of buckwheat dough are improved, and the rough mouthfeel of the product is improved by applying advanced technologies such as vacuum freeze drying, ultrafine grinding and bio-enzyme treating. The buckwheat streamed bead produced by the preparation method disclosed by the invention is fine in mouthfeel, can be used as staple food for long-term consumption, higher in flavone content, and is provided with a healthcare function of regulating lipid and reducing blood glucose by buckwheat.