The invention provides a compound 
fermentation biological feed and a preparation method thereof. The method comprises the steps of 
fermentation of base material components, a 
fermentation process and the like. The compound fermented biological feed is prepared from the following raw materials in parts by weight: 65 to 72 percent of corn, 5 to 12 percent of 
soybean meal, 9 to 12 percent of rice 
bran meal, 7 to 10 percent of 
bran, 1.0 to 1.5 percent of mountain flour, 0 to 0.2 percent of 
calcium hydrophosphate, 0.5 to 0.9 percent of 
lysine, 0 to 0.1 percent of 
methionine, 0.1 to 0.2 percent of 
threonine, 0 to 0.1 percent of 
tryptophan, 0.2 to 0.5 percent of table salt, 0 to 0.05 percent of 
phytase, 0.01 to 0.03 percent of multi-
vitamin and 0.2 to 0.3 percent of multi-mineral. The six fermentation strains, namely 
lactobacillus rhamnosus, 
lactobacillus plantarum, 
bacillus licheniformis, 
bacillus subtilis, 
saccharomyces cerevisiae and candida utilis, are adopted. According to the present invention, the high-quality biological fermentation feed is produced by using the conventional complete feed, the 
nutrition is balanced, the 
palatability is good, the concentration of 
ammonia gas and 
hydrogen sulfide in the 
manure odor of the fattening pigs can be significantly reduced by more than 60%, and the air environment of the pig house is improved; meanwhile, the 
feed conversion ratio can be reduced by 14.5%, the production performance is effectively improved, and the feed cost is remarkably reduced.