The invention discloses small steamed buns with an eyesight improving effect and a preparation method thereof. The small steamed buns are prepared from the following raw materials: starch, low-gluten flour, egg liquid, white granulated sugar, milk powder, grain flour with the eyesight improving effect and a color-mixing and flavoring agent, wherein the grain flour with the eyesight improving effect is millet flour which accounts for 20%-40% of the total weight of the small steamed buns or purple rice flour which accounts for 3%-10% of the total weight of the small steamed buns or a mixture of the millet flour and the purple rice flour, which accounts for 20%-45% of the total weight of the small steamed buns; and the color-mixing and flavoring agent is one or the mixture of more of fructose syrup, maltose, beta-carotene, lactose and ethyl maltol. A preparation method of the small steamed buns comprises the following steps: preparing fermentation liquid; kneading dough; dicing; rolling; and burning. The small steamed buns prepared by the process provided by the invention have the characteristics of complete shape, golden yellow color and luster, crispy and delicious taste, rich milky flavor, uniform fine-hole-shaped inner part, moderate sweetness, and capability of being melted after the small steamed buns are eaten, and are good for protecting the eyesight.