Feed capable of improving production and reproductive performance of sows and preparation method thereof

The invention provides a feed capable of improving production and reproductive performance of sows and a preparation method thereof. The preparation method comprises the following steps that corn flour is added into water, and grinding is carried out to obtain corn steep liquor; then beta-amylase is added into the corn steep liquor, primary enzymolysis and enzyme deactivation are carried out, alpha-glucosidase is added, and secondary enzymolysis and enzyme deactivation to are carried out obtain enzymolysis corn steep liquor; soybean meal powder is added into water, grinding is carried out to obtain soybean meal slurry, a complex microbial inoculant is inoculated, and fermenting is carried out to obtain fermented soybean meal slurry; then fresh purple sweet potatoes and raspberries are correspondingly mashed and uniformly mixed, then theaflavin and ferroporphyrin are added, water is added, grinding is carried out into thick liquid, then beta-cyclodextrin is added, and homogenizing is carried out to obtain prem