NOVELTY - Preparing organic fertilizer, by stacking raw materials, adding enzymes and bacterial strains having degradation ability to stacked materials, fermenting materials, putting animal manure, fermenting strains, lipase and protease on stacked materials, sterilizing pre-treated materials, spraying culture broth containing effective microorganisms (EM) on sterilized materials, fermenting mixture, monitoring temperature, drying fermented compost, sieving dried compost, crushing sieved product, sieving powder, granulating powder and packaging fertilizer granules.    USE - The method is useful for preparing organic fertilizer (claimed).    ADVANTAGE - The method is environmentally-friendly, and enables to prepare organic fertilizer that regulates ecological balance of microorganisms in soil, decomposes largely into organic matter, minerals, and organic and inorganic components in soil, eliminates compaction, salinization and desertification of soil caused by use of chemical fertilizers for many years, and cultivates plants in an environmentally-friendly manner. The method enables effective and comprehensive utilization of animal manure, prepares organic fertilizer having good quality and stability, saves energy, and consumes less energy.    DETAILED DESCRIPTION - Method for preparing organic fertilizer, involves (a) selecting raw materials, collecting selected raw materials, stacking collected materials, adding enzymes and bacterial strains having degradation ability to stacked materials, performing pretreatment of materials in presence enzymes and bacterial strains for carrying out degradation of crude fiber in materials with high crude fiber content, allowing first fermentation process to occur, completing first fermentation process, adding bacterial strains capable of degrading crude fiber and lignin, cellulase, xylanase and amylase to stacked materials, and putting animal manure, fermenting strains, lipase and protease on stacked materials, (b) conveying pre-treated materials having carbon-nitrogen ratio of 20-30 into chamber for aging organic fertilizer, adding pre-treated materials to fermentation machine with stirrer and UV sterilization device, and subjecting the pre-treated materials to sterilization using UV sterilization device for 2 hours, (c) spraying culture broth containing effective microorganisms (EM) uniformly on fermenting materials, and mixing broth and fermenting materials to obtain compost mixture, (d) carrying out fermentation at constant temperature of 35-45 degrees C inside the fermentation machine, stirring mixture for 8 hours, adding aerobic and anaerobic EM bacterial strains to the mixture, and decomposing organic matter, nitrogen, phosphorus and potassium from organic waste, and (e) fermenting mixture for 8 hours, transferring decomposed mixture to aging chamber using forklift, stacking decomposed mixture into heaps having height of 2-3 m, incubating decomposed mixture for 7-21 days, inserting temperature sensor into the heaps, performing real-time monitoring of temperature inside the heaps, ventilating the heaps using long stick when temperature of heaps reaches 60 degrees C, maintaining temperature of compost at 60 degrees C or less, allowing complete degradation and conversion of compost into stable humus, drying fermented compost at low temperature, where drying temperature is not greater than 60 degrees C, putting dried product on sieve plate of thermostatic drying chamber, where the sieve plate is disposed horizontally at 75 cm above ground surface of the thermostatic drying chamber, the sieve plate is provided with ventilating holes, and bottom portion of the drying chamber is provided with a fan, maintaining constant temperature inside the drying chamber during ventilation process, sieving dried compost through drum sieve, grading sieved product, putting graded product into chain crusher, crushing graded product, sieving crushed product to obtain powder, removing impurities from the powder, conveying impurities into drum through outlet for discarding impurities, crushing powder again using crusher, sieving crushed product, screening sieved product, mixing organic fertilizer powder using vertical mixer for 2 minutes, granulating mixture using granulator, conveying granules to packaging chamber, packaging organic fertilizer granules, and transporting packaged product as finished product by belt conveyor. The raw materials comprise straw and animal manure. The straw is at least one chosen from rice straw, wheat straw, corn straw and Sorghum straw. The animal manure is at least one chosen from chicken manure, cattle and sheep manure and pig manure. The animal manure comprises 25 parts chicken manure, 25 parts cattle and sheep manure and 35 parts pig manure. The straw comprises 5 parts corn straw and 10 parts wheat straw.