A method of producing cattle and sheep complete feed by double fermentation comprises the steps of bacterium cultivation, preparation of main materials, preparation of fine materials, primary fermentation of a premix, and secondary fermentation of the feed; the bacterium cultivation refers to: culturing a purchased bacterium with a primary culture medium and then with a secondary culture medium; the main materials include bagasse, sugarcane ends, and a mixture of one or more of fresh grass, cassava stem leaf, fresh grasses, wheat straw, rice straw, corn stalk, paper mulberry and weeds; the fine materials include grain feed, byproducts from grain processing, and a mixture of nutrients required by animals; the primary fermentation of the premix refers to: mixing the fine materials with a fermentation bacterium, culturing by anaerobic fermentation to obtain the premix, and sealing for use; the secondary fermentation of the feed refers to: mixing the main materials and the premix and culturing by anaerobic fermentation for 7-15 days to obtain the double-fermented cattle and sheep complete feed. The feed produced by double fermentation has good palatability.