The invention discloses a probiotic fermented feed additive which has effects of improving digestion and absorption performance of pigs, enhancing the body immunity, promoting the healthy production of the pigs and increasing the yield of high-quality meat products. The fermented Chinese herbal medicine feed additive is prepared from herba dendrobii, radix rehmanniae preparata, seaweed, herba houttuyniae, fructus ligustri lucidi, herba gynostemmatis, radix angelicae sinensis, radix polygoni multiflori, flos lonicerae, rhodiola rosea, rhizoma atractylodis macrocephalae, radix glycyrrhizae, folium steviae rebaudianae and other Chinese herbal medicines through a process of 'ultrasonic assisted degradation of Chinese herbal medicines and multi-strain two-step fermentation'. The probiotic fermented feed additive has double advantages of the Chinese herbal medicines and probiotics, can effectively control the intestinal health of the pigs, treats both manifestation and root cause of a disease, strengthens the primordial qi and reinforces the vital essence, keeps the intestinal microecological balance and the best immune status, increases the digestion and absorption rate of nutrients, improves the body immunity of the pigs, increases the breeding income, reduces the breeding risk, can be used to replace antibiotics, has no adverse effects on the pigs, is safe to use, has no drug residues, drug resistance and other problems, and has broad market prospects.