The invention provides a compound microorganism feed additive which comprises aspergillus niger, bacillus subtilis, enterococcus faecalis and oligosaccharide with the mass faction ratio being 50-60:10-20:10-20:5-10. According to the strain living cell counts, the count of aspergillus niger spores is (1-10)*10<8> cfu / g, the count of bacillus subtilis is (1-10)*10<9> cfu / g, the count of enterococcus faecalis is (5-10)*10<9> cfu / g, and the total bacteria count is not smaller than 3*10<9> cfu / g. The compound microorganism feed additive has the good disease resistance and can enhance the animal immunity. Due to the fact that the oligosaccharide is added, the animal immunity can be improved, and infectious diseases are prevented. The compound microorganism feed additive is obtained in a solid fermentation mode, the production technology and equipment are simple, operation is easy, the source of production raw materials is wide, and the price is low, so that the production cost is greatly lowered, waste materials are recycled, environmental pollution is reduced, and sustainable development is achieved. Due to the application of the compound microorganism feed additive, the piglet disease resistant ability is remarkably improved, and the death rate is decreased. The compound microorganism feed additive is of great importance in promoting sustainable development of poultry farming.