NOVELTY - Method for preparing organic fertilizer, involves (a) mixing e.g. maize straw and sesame straw, adding e.g. water and urea to the straw particles, and processing to obtain mixture A, (b) mixing chicken manure and pig manure, and sterilizing the mixture B, (c) mixing e.g. crushed rapeseed cake and crushed deciduous broadleaves, processing, and performing aerobic fermentation to obtain mixture C, (d) mixing e.g. mixtures A, B and C, and processing the mixture to obtain mixture D, and (e) adding e.g. plant ash to the mixture D, and processing the mixture.    USE - The method is useful for preparing organic fertilizer for root vegetables (claimed).    ADVANTAGE - The method prepares fertilizer which satisfies the nutrient requirements for growth of root vegetables, conditions soil, activates active soil microorganism rate, overcomes problem of soil hardening, and increases soil-air permeability.    DETAILED DESCRIPTION - Method for preparing organic fertilizer, involves (a) crushing the straw of 0.5-0.8 cm, mixing maize straw, wheat straw, soybean straw and sesame straw in a mass ratio of 3:2:2:1, respectively adding 50% water, 0.03% urea and 0.8% ammonium hydroxide to the straw particles, stirring and uniformly mixing the components, sealing the mixture, and naturally allowing the mixture at static condition for 3-8 days to obtain mixture A, (b) subjecting the chicken manure to UV radiation treatment for 50-70 minutes, then subjecting the chicken manure to the ozone sterilization for 30-50 minutes, where the chicken manure is turned once for every 10 minutes, subjecting the pig manure to UV radiation treatment for 60-80 minutes, then subjecting the pig manure to ozone sterilization treatment for 30-50 minutes, where the pig manure is turned once for every 20 minutes, uniformly mixing chicken manure and pig manure in a mass ratio of 10:5, and sterilizing the mixture to obtain mixture B, (c) crushing the rapeseed cake to 20-30 meshes and deciduous broadleaves to 20-30 meshes, uniformly mixing the crushed rapeseed cake, crushed deciduous broadleaves and water in a mass ratio of 1:2:1, mixing Aspergillus niger and yeast with the mixture in a mass ratio of 2:1, adding peanut shell, where the content of the deciduous broadleaves with respect to total mass of the mixture is 3%, and performing aerobic fermentation at 28 degrees C for 5-7 days to obtain mixture C, (d) filtering and uniformly and homogeneously mixing the mixture A, mixture B, mixture C, shell powder and sodium humate in a mass ratio of 6:10:2:0.2:0.3, adding 2 %mass effective microorganisms (EM) to the mixture, and performing aerobic fermentation process at 30 degrees C for 5-8 days to obtain mixture D, and (e) adding 0.5 %mass plant ash and 0.1 %mass charcoal powder to the mixture D, uniformly mixing the components, subjecting the mixture to ozone sterilization, then drying the mixture at 50-55 degrees C for 24-36 hours, packaging the mixture, and subjecting the mixture to UV sterilization to obtain product.