PURPOSE: A manufacturing method of fermented feed additive is provided by using an useful microorganism along with Curcumae longae Rhizoma, Houttuynia cordata, Japanese apricot, Rubi Fructus, mulberry, and a grain fermentation source. CONSTITUTION: A manufacturing method of ream water fermentation feed additive comprises the steps of: (step 1) mixing a Curcumae longae Rhizoma crushed material, a Houttuynia cordata crushed material, a Japanese apricot crushed material, a Rubi Fructus crushed material, a mulberry crushed material, and a grain fermentation source, followed by controlling a moisture content to be 45 to 55% and pH to be 4.5 to 5.0； (step 2) preparing a primary fermentation product by mixing yeast to the mixture and fermenting the mixture at a temperature of 25 to 30>；= for 3 to 5 days, followed by controlling pH to be 5.0 to 6.0； (step 3) preparing a secondary fermentation product by fermenting the primary fermentation product with lactobacillus at a temperature of 45 to 50>；= for 1 to 3 days； and (step 4) drying the secondary fermentation product with hot air at a temperature of 15 to 25>；= for 20 to 24 hours to prepare dried natural fermentation feed additive with a moisture content of 10 to 15% and pH of 5.5 to 6.5. In the step 1, the mixture contains 10 to 30 wt% of the Curcumae longae Rhizoma crushed material, 10 to 30 wt% of the Houttuynia cordata crushed material, 5 to 20 wt% of the Japanese apricot crushed material, 5 to 20 wt% of the Rubi Fructus crushed material, 5 to 20 wt% of the mulberry crushed material, and 20 to 40 wt% of the grain fermentation source. As for the yeast, Saccharomyces cerevisiae is used. [Reference numerals] (AA) Curcumae longae Rhizoma, Houttuynia cordata, Japanese apricot, and Rubi Fructus； (BB) Soybean cake； (CC) 60-120 mesh crushing； (DD) Inoculating yeast； (EE) Solid fermenter； (FF) Inoculating lactobacillus； (GG) Primary fermented product； (HH) Secondary fermented product； (II) Drying with hot wind； (JJ) Natura
