The invention relates to a compound feed for lactation sows and a preparation method of the compound feed, and belongs to the technical field of a pig feed. The compound feed comprises the raw materials of corn, soybean meal, corn germ meal, DDGS, rice bran meal, calcium hydrogen phosphate, stone powder, edible salt, complex vitamins for breeding boars, trace elements for breeding boars, soybean oil, an antioxidant, a solid mildewproof agent, a sweetening agent, high temperature resistant phytase, choline chloride, bile acid, and heat resistant stress additive, wherein the heat resistant stress additive comprises the raw materials of threonine, arginine, vitamin C, gamma-aminobutyric acid, and a bacillus subtilis microecological preparation. According to the compound feed for lactation sows, the food consumption of bodies of the sows can be increased, the intake quantity of nutrients is increased, mammogenesis is promoted, heat stress of the bodies of the sows can be relieved, the conversion rate of the compound feed is increased, and comprehensive production performance of the bodies of the sows can be improved. According to the preparation method of the compound feed, steam granulation and rotary drying for two times are adopted, so that the surface heating uniformity of the compound feed is improved, and the compound feed is simple to prepare, convenient to shape and convenient to control.