NOVELTY - Preparing biological organic fertilizer involves mixing 60-80 parts manure, 10-20 parts straw, 10-15 parts waste water and 3-5 parts fermenting strain, stirring, putting the mixture into a fermentation tank; pre-fermenting the mixture at 20-25 degrees C for 72-90 hours; dehydrating the mixture; again fermenting the dehydrated mixture, adding 5-8 parts bio-fungus, and adding oxygen in fermented material; performing second fermentation at normal temperature, aerating the fermentation material, to obtain fertilizer and then granulating the fertilizer; and packaging the granular fertilizer.    USE - For preparing biological organic fertilizer (claimed).    ADVANTAGE - The process is short time process; has high efficiency of composting organic fertilizer, and prepares product has enhanced organic fertility, brightness and beautiful appearance.    DETAILED DESCRIPTION - Preparing biological organic fertilizer involves mixing 60-80 parts manure, 10-20 parts straw, 10-15 parts waste water and 3-5 parts fermenting strain, stirring the mixture until water content is 60-80%, putting the mixture into a fermentation tank; pre-fermenting the mixture in the fermentation tank, at 20-25 degrees C for 72-90 hours; transferring the prefermented mixture into extrusion separating device to obtain mixture having water content of 30-40%; again fermenting the dehydrated mixture in the fermentation tank at 80-90 degrees C for 90-120 hours, in the process of fermenting, adding 5-8 parts bio-fungus, and adding oxygen in fermented material; after first fermentation obtained the fermented material having high fertilizer stack that transfer to the shed, performing second fermentation at normal temperature for 10-15 days in summer and autumn, or for 20-25 days in winter and spring, aerating the fermentation material, to obtain fertilizer and then granulating the fertilizer in the rotary drum device, where rotary drum device treated with amino acid; and packaging the granular fertilizer and drying to obtain finished product.