The invention discloses nutrient for improving productivity of nursing sows and a preparation method thereof. The nutrient for improving productivity of nursing sows comprises, by weight, 5-20 parts of Angelica acutiloba root, 10-25 parts of Astragalus root, 5-25 parts of cowherb seed, 5-20 parts of beautiful sweetgum fruit, 10-25 parts of hawthorn fruit, 10-25 parts of malt, 5-25 parts of dried orange peel, 5-25 parts of medicated leaven, and 10-25 parts of motherwort. The preparation method includes cleaning pharmaceutical materials, and drying and crushing to obtain powders of the pharmaceutical materials; weighing the crushed powders of the pharmaceutical materials according to a ratio of the nutrient, mixing well, and subpackaging. By the use of the nutrient for improving productivity of nursing sows, milking ability of sows can be improved effectively, anorexia and constipation in sows can be avoided, normal oestrus of the sows after weaning is promoted, and yellow and white scours of newborn piglets are reduced.