NOVELTY - Method for preparing organic fertilizer involves (a) treating straw using alkaline solution, washing treated straw using water and drying washed straw, (b) mixing dried straw and shell powder, spraying acid solution on mixture, and drying mixture, (c) spraying calcium hydroxide solution on mixture, and drying mixture, (d) uniformly mixing treated mixture, rapeseed cake, animal feces, and biological broth, (e) fermenting mixture, spraying diluted biological broth, and again fermenting mixture, and (f) mixing fermented material, earthworm manure, and rapeseed cake.    USE - The method is useful for preparing organic fertilizer (claimed).    ADVANTAGE - The method enables to prepare fertilizer which is easily absorbed by plants, soluble in water, and rich in chitin and calcium, and continuous cultivation crop, and shortens production time of organic fertilizer.    DETAILED DESCRIPTION - Method for preparing organic fertilizer involves (a) slicing straw into 2-5 cm pieces, spraying alkaline solution of pH 10-11 on straw pieces, until straw is moistened, allowing straw to react with alkaline solution for 2-5 hours, washing treated straw using water and drying washed straw, (b) mixing dried straw obtained in the step (a) and shell powder in a ratio of 4-10:1, spraying acid solution of pH 3-4 on mixture, until mixture is moistened, allowing mixture to react with acid solution for 1-3 hours, and drying mixture, (c) adding mixture obtained in the step (b) into a blender, spraying 40-50% calcium hydroxide solution on mixture for adjusting pH between 6.5-7.5, stirring mixture, and drying mixture, (d) uniformly mixing treated mixture obtained in the step (c), rapeseed cake, animal feces, and biological broth in a ratio of 100:20-30:20-40:1-3, piling mixture, and fermenting mixture for 10-15 days, (e) fermenting mixture at 56-60 degrees C, spraying 50-100 times diluted biological broth when temperature reaches 65 degrees C, and fermenting mixture for 20-30 days, and (f) mixing fermented material obtained in the step (e), earthworm manure, and rapeseed cake in a ratio of 20-30:5-6:2-5.