The invention discloses a mixed feed for nursery piglets, and a preparation method thereof. The feed is composed of expanded cereal, expanded soybean meal, fermented soybean meal, first-stage steam fishmeal, monosaccharides and/or disaccharides, composite trace elements, organic trace elements, composite vitamins, vegetable oil, an antibiotic additive, an acidifier, an enzyme preparation, a beneficial bacterium, phytase, a sweetener, frankincense, choline chloride, stone powder, calcium hydrogen phosphate, lysine hydrochloride, threonine, salt and ethoxyquinoline. An expansion processing technology is adopted to carry out heat treatment of cereal and soybean meal in order to improve the starch gelatinization degree, denature proteins and reduce the content of antigens, so the alimentary canals of piglets are elongated, and the in-vitro pre-digestion of nutritional components is realized. The mixed feed for nursery piglets prepared through the processing technology is loose, soft and crisp particles, just melts in the mouth, and allows nursery piglets to have the advantages of high feed intake, easy digestion, fast growth and good appearance.