NOVELTY - Preparing organic fertilizer, comprises (a) preparing orange powder residue; (b) pulverizing organic materials, to obtain organic materials mixed powder; (c) stirring steps (a) and (b) products, and adding crude fiber for carrying out activation degradation using composite bacteria; (d) carrying out degradation of crude fiber, sprinkling pesticides, stirring, and carrying out bulk fermentation; (e) composting; and (f) spreading out compost to dry, measuring the moisture content, packaging the material under post-fermentation conditions or drying-granulating, to obtain the final product.    USE - The method is useful for preparing organic fertilizer (claimed).    ADVANTAGE - The method utilizes waste residue completely, so as to reduce stacking of waste residue, and thus it is environmental friendly; reduces production of bad odor during fermentation process by utilizing deodorization treatment agent, and pesticides which kills flies; saves resource; has simple operation procedure; and is economical.    DETAILED DESCRIPTION - Preparing organic fertilizer, comprises (a) crushing orange pericarp using a pulverizer to 1-3 cm, adjusting the pH of citrus pericarp to 5.5-7 by adding lime, adding a deodorization treatment agent, completely mixing uniformly, to obtain orange powder residue; (b) pulverizing organic materials with a pulverizer to 5-10 mm, to obtain organic materials mixed powder; (c) uniformly stirring steps (a) and (b) products, adjusting to mixed materials, controlling moisture content of the mixed material to 45-65%, adding crude fiber for carrying out activation degradation using composite bacteria, piling into a ridge, and covering straw mat to carry out degradation of crude fiber; (d) carrying out degradation of crude fiber for 6 hours, uncovering, adding straws compost maturity composite bacteria spread as a cultivation agent, sprinkling pesticides, stirring, and carrying out bulk fermentation by covering straws; (e) composting to promote water loss, and prevent overheating so as to inhibit microbial activity, initially turning the compost for first 10 days under post-fermentation conditions, measuring the core temperature while turning the compost once in every 5 days for 5 times, and allowing to compost for 38-42 days; and (f) spreading out compost to dry, measuring the moisture content, packaging the material under post-fermentation conditions or drying-granulating, to obtain the final product.