The invention discloses a food additive for adjusting and reducing blood fat, which is prepared from oat bran, wheat bran, lecithin, a tartary buckwheat extract, a folium ginkgo extract, red beans, perilla seeds, perilla leaves, coix seeds, almonds, jujube kernels, mulberry leaves, chrysanthemum, Chinese wolfberry, pawpaw, rhizoma zingiberis, liquorice, white hyacinth beans, hawthorn, malt, radish seeds, endothelium corneum gigeriae galli, yam, orange peel, tuckahoe, fingered citron, fructus cannabis,lily, fructus momordicae and brush cherry seeds according to the method of: drying and crushing the oat bran to obtain oat fiber after the oat bran is added with water and is subjected to extrusion expansion treatment; drying and crushing the wheat bran to obtain wheat fiber after the wheat bran is subjected to acid treatment to remove starch and is subjected to alkali protease treatment to decompose protein; extracting tartary buckwheat shells and folium ginkgo by ethanol to obtain the tartary buckwheat extract and the folium ginkgo extract; crushing other raw materials; and mixing the obtained materials according to the mixture ratio of raw materials, stirring the mixture, and sieving the mixture to obtain the food additive. The food additive has the unique effect which cannot be substituted by medicaments, has a simple manufacturing method, and has large market potential.