NOVELTY - A microbial fermentation feed comprises 400-600 g corn, 50-200 g wheat bran, 150-250 g soybean meal, 20-40 g cottonseed meal, 20-40 g rapeseed meal, 50-100 g swelled soybean flour, 20-40 g fish meal and 5 g tourmaline powder.    USE - A microbial fermentation feed.    ADVANTAGE - The fermentation feed not only can promote growth of animal, regulate normal flora of gastrointestinal tract and maintain ecological balance but also can improve food digesting rate and biological valence, reduce serum cholesterol, control endotoxin, restrict growth of putrefying bacteria in intestinal tract and improve immunity of organism. It also has antagonism to pathogen, such as dysentery bacillus, Corynebacterium diphtheriae, Bacillus paratyphosus, Campylobacter and staphylococcus, and can reduce breeding cost and effectively prevent abuse of antibiotics.    DETAILED DESCRIPTION - A microbial fermentation feed comprises 400-600 g corn, 50-200 g wheat bran, 150-250 g soybean meal, 20-40 g cottonseed meal, 20-40 g rapeseed meal, 50-100 g swelled soybean flour, 20-40 g fish meal and 5 g tourmaline powder. The strain comprises Lactobacillus brevis, Lactobacillus delbrueckii subsp. lactis, Lactobacillus paracasei, Lactobacillus brevis, Lactobacillus pentosaceus, Lactobacillus, Lactobacillus plantarum and Lactobacillus acetotolerans. Each strain is obtained by separating lactic acid bacteria in pig manure, intestinal tract of pig and fermentation feed, selecting one single flora from good-quality L. brevis, L. delbrueckii subsp. lactis, L. paracasei, L. brevis, L. pentosaceus, Lactobacillus, L. plantarum and L. acetotolerans, purifying and culturing on inclined plane. The feed preparation method comprises: (A) preparing culture medium for primary activating culture comprising 10 g soybean peptone, 6 g beef powder, 6 g yeast powder, 40 g glucose, 40 g lactose and 200 ml distilled water, weighing each component and dissolving in 200 ml distilled water, filling the prepared culture medium for primary activating culture to a 400 ml triangular bottle; sterilizing by high pressure steam for 20 minutes at 121 degrees C, and then putting in a refrigerator at - 4 degrees C for use; (B) respectively selecting single flora on inclined planes of L. brevis, L. delbrueckii subsp. lactis, L. paracasei, L. brevis, L. pentosaceus, Lactobacillus, L. plantarum and L. acetotolerans, respectively inoculating to 20 ml primary activating culture medium, anaerobically statically culturing for 12-18 hours at 40 degrees C, when pH of primary activation culture is 3.8-4.5 and the fermentation product has acid flavor, reaching the fermentation effect; (C) preparing the secondary expanding culture medium comprising 1 kg soybean peptone, 10 kg deionized water and 200 g sodium chloride, weighing each component and dissolving in 10 kg deionized water, sterilizing for 20 minutes by high pressure steam at 118 degrees C, and then putting in a refrigerator at - 4 degrees C for use; inoculating the primary activation culturing strain liquid of each strain (respectively 20 ml) to 10 kg secondary expanding culture medium, anaerobically statically culturing for 24 hours at 40 degrees C, when pH of primary activation culture is 3.8-4.5 and the fermentation product has acid flavor, reaching the fermentation effect; (D) preparing third-time expanding culture medium comprising 350 g brown sugar, 10 g sodium chloride and 350 kg deionized water, weighing each component and dissolving in 10 kg deionized water, sterilizing for 20 minutes by high pressure steam at 121 degrees C, inoculating 10 kg culture liquid undergoing secondary expanding culture to 350 kg third-time culture medium, anaerobically statically culturing for 24 hours at 40 degrees C, (E) uniformly stirring 10 kg strain liquid undergoing third-time expanding culture, 250 g brown sugar, 100 kg deionized water and 1000 kg main materials by a miniature stirrer, filling the stirred feed needing fermenting to 100 kg sealed barrel, sealing the barrel, keeping room temperature at 25 degrees C, fermenting for 8 hours in sealing manner to obtain the product when the fermentation feed has flavor of biscuit.