The invention discloses a feed additive for improving the stress resistance, meat color and meat quality of a grown fattening pig and application thereof. The feed additive comprises the following components in parts by weight: 0.3-0.5 part of L-carnitine, 10-20 parts of betaine, 10-15 parts of electrolyte, 1-3 parts of selenium preparation, 2-5 parts of iron preparation, 3-5 parts of magnesium preparation, 0.5-1 part of chromium preparation, 1-2 parts of decavitamin, 5-10 parts of compound amino acid, 1-5 parts of tea polyphenol, 5-10 parts of isatis root and 20-61.2 parts of carrier. The feed additive provided by the invention has the following advantages: (1) the feed additive is composed of nutrient substances, Chinese herbal medicines and plant extracts, has non-toxic side effect, and is beneficial for the health of animals and human beings; (2) the raw material used by the invention is stable in resource, low in price, simple in production process, easy for industrial production; and (3) the feed additive provided by the invention can be used for rapidly supplementing various nutritive stress resisting substances, reliefing the stress of animals, improving the meat color and meat quality, and reducing the drip loss.