The invention belongs to the technical field of vinegar, and particularly relates to a preparing method of raw stock vinegar prepared from nine kinds of cereals. The raw stock vinegar prepared from nine kinds of cereals is prepared from, by mass, 20-25 parts of millet, 18-22 parts of barley, 15-20 parts of maize, 32-35 parts of sorghum, 10-12 parts of wheat, 8-12 parts of peas, 60-65 parts of wheat bran, 30-33 parts of rice hulls, and 25-29 parts of chaff. The preparing method of the raw stock vinegar prepared from nine kinds of cereals specifically comprises the following steps of S1, cleaning and mixing; S2, cooking; S3, fermentation; S4, fumigation; S5, vinegar drenching; S6, ageing. According to the preparing method, the nine cereal raw materials serve as main processing materials, andthe nutritive ingredients are rich; the raw stock vinegar is thick in texture, rich in mouthfeel, sweet in after-taste, high in nutritional value and rich in nutritive ingredient.