The invention discloses an antibiotic free, hormone free and harmful additive free biological mixed feed capable of improving quality of meat and suitable for feeding of various meat animals, and a production method thereof. The biological mixed feed comprises the following materials, by weight: 8-10% of biological fermentation cotton seed meal, 3-5% of polypeptide biological blood powder, 80-84% of mixed forage powder, 3-5% of feed additive and 1-5% of plant oil. According to exogenous enzyme and microbial fermentation, macro-molecule protein raw materials are decomposed into polypeptides and small peptides, so as to degrade anti-nutritional factors like non-starch polysaccharides in the forage and increase utilization rate of the forage; meanwhile, abundant B-group vitamin, free amino acid and organic acidity are generated during a fermentation process to promote deposition of flavor amino acid, inosinic acid and unsaturated fatty acid in muscle, so as to enhance quality of meat. Freshwater fish, fryers and growing and fattening pigs fed by the biological mixed feed for animals of the invention have characteristics of fast growth speed, and elastic, chewy, delicious and strongly fragrant fish meat, chicken and pork. The method of the invention is simple, requires no special equipment and is suitable for industrialized production.