The invention discloses a method for preparing multifunctional ready-to-use fermented feed for animals by a composite fermentation bacteria wet process, comprising the following steps of: 1, activating bacteria, and culturing in a large scale, activating frozen lactobacillus plantarum, lactobacillus acidophilus, bacillus subtilis, streptococcus faecalis,and candida utilis, and culturing in a large scale to respectively obtain 108-109cfu/mL of lactobacillus plantarum suspension liquid, 10<8>-10<9>cfu/mL of lactobacillus acidophilus suspension liquid, 10<8>-10<9>cfu/mL of bacillus subtilis suspension liquid, 10<8>-10<9>cfu/mL of streptococcus faecalis suspension liquid and 10<8>-10<9>cfu/mL of candida utilis suspension liquid; 2, preparing a composite probiotic microecological preparation for the animals; and 3, preparing multifunctional fermented feed for the animals. The multifunctional ready-to-use fermented feed for the animals, prepared by the composite fermentation bacteria wet process, is simple in process step, low in material cost, and suitable for commercial production and has a wide application range.