The invention discloses a preparation method of a sawdust feed. The preparation method comprises the following flows of: material selection, grinding, primary preparation, alkalization, rinsing, mixing, and fermentation to obtain finished product. The feed is prepared by grinding and alkalizing nontoxic, mildew-free and foreign-matter-free sawdust and straws and then adding various ingredients, mixing the materials uniformly and naturally fermenting the mixture in a closed container. The feed is nontoxic, harmless and hormone-free, has good palatability, can be fed to livestock and poultry and saves grains. The method has the advantages of low equipment investment, simple and practicable process, energy conservation and environment friendliness and good economic and social benefits.