The invention discloses an organic material inoculant, which is a complex microbial community composed of actinomycetes, yeast, lactic acid bacteria, bacillus and photosynthetic bacteria; the effective active bacteria content is 0.5-100000000 unit / g, wherein 40-60% thereof is actinomycetes, the dosage form is powder; the particle diameter of the powder is less than or equal to 0.2 mm, the water content is less than or equal to 20%; the pH value range is 5.5-7.5; and the invention has wine yeast smell. The optimal combination in the complex microbial community is as follows: 50 parts of actinomycetes, 10 parts of yeast, 10 parts of lactic acid bacteria, 15 parts of bacillus and 15 parts of photosynthetic bacteria. The preparation process flow of the material inoculant comprises preparing culturing pot, preparing material, dosing material, loading, culturing and fermenting, drying, crushing, detecting, packaging and storing. The organic material inoculant of the invention is a special organic material inoculant for vinegar residue, cassava residue and other organic materials; the effective active bacteria content is high, the degrading and rotting speed of cellulose is fast. The invention has disadvantages of fast temperature rise, high temperature, strong adaptability and simple preparation; the use effect is good, and the invention is especially suitable for self-culturing and self-consumption in substrate production enterprise.