The invention discloses a mixed grain rice vinegar and a production method of the mixed grain rice vinegar. The mixed grain rice vinegar is a liquid product prepared from black tartary buckwheat, oat, broomcorn, wheat, black glutinous rice and white corn serving as main materials as well as sticky rice and a plurality of Chinese herbal medicines serving as auxiliary materials through fermentation together. The production method comprises the following steps of: cleaning the sticky rice, and then soaking and steaming; respectively crushing the Chinese herbal medicines, the black tartary buckwheat, the oat, the broomcorn, the wheat, the black glutinous rice and the white corn; mixing according to proportion and fermenting for 15 days to obtain a brewing mass; turning over and mixing the brewing mass and performing acidification and fermentation twice; ageing mature brewing mass for three months; then placing the aged brewing mass into a vinegar sprinkling pond; sprinkling cold boiled water slowly, soaking, discharging the vinegar liquid from the bottom of the pond to obtain raw vinegar; and finally, heating the raw vinegar, cooling and bottling, checking out to obtain a finished product. The mixed grain rice vinegar has a health-care function, is natural and pollution-free, can be used for cooking as a seasoning in various occasions such as homes, dining rooms, restaurants and tourist sites. In addition, the mixed grain rice vinegar is delicious in taste, has pure flavor, is soft and lasting in aftertaste, is mellow and sweet, is rich in nutrition and has a unique style.