The invention relates to the technical field of pig feeds, in particular to a fermented feed capable of promoting growth of live pigs, and a preparation method and use method of the fermented feed. The fermented feed is mainly prepared from raw materials of distillers' grains, watermelon peel, peanut vines, helianthus annuus, bulbo-phylulm ambrosirm, polygonum aviculare, pennisetum giganteum, humulus scandens, populus tomentosa, beta vulgaris, corydalis yanhusuo, polygala tenuifolia, scirpus triqueter, eutrema yunnanense, hyssopus officinalis, uncaria rhynchophylla, bombyx mori Linnaeus, crataegus pinnatifida, pinus armandi franch, stone powder, dicalcium phosphate, brown sugar, an enzyme preparation, table salt, microorganisms and the like through steps of treating the raw materials, performing blending and mixing, adopting a lighting stir-frying with bran method, performing fermentation and the like. The formula of the fermented feed is most scientific and reasonable; the fermented feed is rich in nutrition and good in palatability, and has the health-care efficacy of clearing heat, removing toxicity, invigorating the stomach, promoting digestion, resisting bacteria, disinfectinginsects, calming and soothing the nerves, resisting eclampsia, stimulating appetite and the like; the constitutions of the live pigs can be effectively strengthened, and the quick growth of the livepigs can be promoted, so that the average weight gain of the live pigs can be increased, the prevalence rate is reduced, the time that the live pigs become full-grown and ready for slaughter is shortened, and further the breeding benefits of the live pigs are effectively increased; and the preparation method of the fermented feed is simple, and the fermented feed is easy to produce.