NOVELTY - Preparing organic fertilizer includes providing organic fertilizer preparation materials, preparing granules of organic fertilizers, preparing controlled-release organic fertilizer granules, providing three sections of controlled-release organic fertilizer granules; and preparing the multi-section controlled release organic fertilizer, the organic fertilizer particle, and the second controlled release organic fertilizer particle, and packaging to obtain organic fertilizer.    USE - Method for preparing organic fertilizer (claimed).    ADVANTAGE - The method is simple and convenient, and has low cost.    DETAILED DESCRIPTION - Preparing organic fertilizer comprises: (A) preparing grape fruit residue, livestock excrement and additive material, then adding water in the obtained mixture, mixing and stirring uniformly, stirring to obtain fermentation product having 40-60 mass% water content, stacking fermentation, carrying out three-stage fermentation at 78-80 degrees C, and sterilizing for 2-4 hours to provide organic fertilizer preparation materials; (B) preparing organic fertilizer particle using biological organic fertilizer particle machine to prepare organic fertilizer particle having diameter at 0.8-1.2 mm; (C) adding 0.8-1 kg chitosan to 0.75 vol.% of 100 kg aqueous acetic acid at a high speed stirring and emulsifying at 3000-4500 revolutions/minute, completely dissolving chitosan in aqueous acetic acid, uniformly spraying the aqueous solution on the chitosan of the organic fertilizer granules, after coating, low temperature drying or mechanical drying tunnel microwave, where the mechanical cryogenic temperature is at 35-45 degrees C for 18-36 hours to release organic fertilizer granules; (D) preparing controlled release organic fertilizer particle including 3-7 kg zein, 4-6 kg wheat gliadin protein, 3-5 kg starch , 4-5 kg glyceryl distearate and 2-3.5 kg Tween-80 (RTM: polyoxyethylene (20) sorbitan monooleate), while adding 15-18 vol.% of 500 kg ethanol aqueous solution at 75-78 degrees C, stirring at 5000-7000 revolutions/minute for 1.5-2.5 hours to obtain a mixed wall material solution; mixing the wall material solution in the coating solution, uniformly spraying on the organic fertilizer granules, after coating uniformly, mechanical low-temperature drying or microwave drying, where the low-temperature drying machinery dries at 30-42 degrees C for 18-36 hours to provide three sections of controlled-release organic fertilizer granules; and (E) preparing the multi-section controlled release organic fertilizer, the organic fertilizer particle, and the second controlled release organic fertilizer particle, where the three sections of controlled release organic fertilizer have a weight ratio of 2:3:3-3:4:5, and packaging to obtain organic fertilizer.