The invention discloses a fermented semi-fluid feed for newborn piglets. The formula of the feed comprises the following raw material components: water, starch, protein, fat, mineral salt, a stabilizer, a suspending agent, compound vitamins, fermented strains and the like. A preparation method of the feed comprises the steps of uniformly mixing the raw material components in a certain sequence, carrying out dissolving, heating, thermal insulation, stirring and constant-temperature fermentation, refrigerating for 1-2 days, so as to obtain the semi-fluid feed, and sealing and packaging the semi-fluid feed. According to the fermented semi-fluid feed, the problems that solid feeds are poor in intake effect, respiratory diseases are easily caused due to dust pollution, and the like are overcome, and furthermore, the problems that liquid feeds are greatly wasted, bacteria are easily propagated, and the like are overcome; meanwhile, after the feed is fermented, the flavor and the digestibility are improved, the palatability is good, the nutrition is balanced, the preservation is convenient, and the wasting is little.