NOVELTY - Preparing biological organic fertilizer granule comprises (i) taking plant source, organic raw material, additive, peat soil and cabbage dregs as raw materials, uniformly crushing, controlling the water content to 55-65%, taking granules with a diameter of 0.5-1 cm, (ii) extruding the raw materials in an extruder to obtain manure granules, and crushing, (iii) mixing the crushed fine powder with e.g. additive to form fermentation material, (iv) stirring and mixing the fermentation material, and crushing into powdery organic fertilizer material, and (v) extruding.    USE - The method is useful for preparing biological organic fertilizer granule.    ADVANTAGE - The method: improves the quality of the fertilizer granule; increases the yield; improves the physical property of soil. The granule reduces 1/3 of the dosage and strengthens the insecticidal and antiseptic effect.    DETAILED DESCRIPTION - Preparing biological organic fertilizer granule comprises (i) taking plant source, organic raw material, additive, peat soil and cabbage dregs as raw materials, uniformly crushing, controlling the water content to 55-65%, taking granules with a diameter of 0.5-1 cm, where the organic raw material comprises (in parts by wt.) chinaberry fruit (4-7), Capsicum straw (15-19), decomposed cow or pig manure (30-40) and saccharomycetes (0.06-0.15), and the plant source comprises Codonopsis pilosula (3-3.5), radix stemonae (2-3.5), rhizoma gastrodiae (3.5-4.5), fructus Forsythia (2-2.5), rhizoma rehmanniae (3-3.5), Platycodon grandiflorum (2.5-3) and etridiazole (9-9.5), (ii) placing the raw materials in an extruder, controlling the temperature to 200 degrees C and the pressure to 10 kg/cm2, extruding to obtain manure granules, crushing the manure granules by a crushing machine and screening, and taking the crushed powder having a diameter of less than 1 mm, (iii) mixing the crushed fine powder with (in parts by wt.) an additive, borax (0.8-2), naphthylacetic acid (0-0.03), gibberellins (0.01-0.04), ammonium sulfate (6-12) and diammonium phosphate (5-9) to form fermentation material, where the additive is zinc, manganese, iron, copper and/or boron amino acid chelate, (iv) stirring and uniformly mixing the fermentation material, conveying to a fermenting pool, stacking the material at about 1 m height in the fermenting pool, covering a permeable heat insulation material onto the surface, controlling the fermentation temperature at 30-35 degrees C, fermenting for 10-14 hours, controlling the pH to 5-6.5 in the fermentation process, reducing the pH to 4.5-4.7 before uncovering the film, stabilizing the air feeding amount during the fermentation period, opening the stack after the two stages of fermentation, drying the fermented material, and making the material drying temperature to not greater than 90 degrees C to obtain the fermented material having a moisture content of 10-12 wt.%, and crushing into powdery organic fertilizer material, and (v) extruding the organic fertilizer material into granular complex fertilizer using a granulating machine.