NOVELTY - Preparing azadirachtin dry powder comprises mixing neem seeds with petroleum ether, extracting, filtering, to obtain extracted liquid, drying the filter residue to obtain neem cake, mixing neem cake with methanol, filtering to obtain filter liquid, concentrating the filtered liquid, mixing concentrated liquid and distilled water, then adding dichloromethane into the mixed liquid, standing and layering, dissolving the neem extract in polar organic solvent A, filtering the mixture, mixing solid precipitate and mixed solvent, washing the solid precipitate, and drying the leachate.    USE - The method is useful for preparing azadirachtin dry powder (claimed), which is useful for preparing biological pesticide.    ADVANTAGE - The method is capable of simply preparing azadirachtin dry powder with high solvent recovery rate in an economically and eco-friendly manner.    DETAILED DESCRIPTION - Preparing azadirachtin dry powder comprises mixing neem seeds with petroleum ether according to ratio of 1:3, stirring and extracting, filtering using a filter to obtain filter liquid and filter residue, adding petroleum ether into the filter residue in mass ratio of 1:3, continuously extracting, filtering to obtain secondary filter liquid and the filter residue, combining two times of filtered liquid, drying the filter residue to obtain neem cake, mixing neem cake with methanol according to ratio of 1:3, stirring for 2-5 minutes, filtering to obtain filter liquid and filter residue, adding methanol into the filter residue according to ratio of 1:3, stirring and extracting for 2-5 minutes, repeating the above steps for 3 times, collecting 3 times of the filtered liquid, then concentrating the filtered liquid according to the conventional method to obtain filtered liquid concentrate volume of 1/3-1/4, oscillation mixing concentrated liquid and distilled water, then adding dichloromethane into the mixed liquid, standing and layering, collecting lower layer, standing and layering to collect dichloromethane layer, combining the two layers and concentrating to obtain the extract, dissolving the neem extract in polar organic solvent A at mass ratio of 1:3-9 to obtain azadirachtin, dissolving azadirachtin in solvent B according to mass ratio of 15-60:1 to obtain azadirachtin mixture, filtering the mixture using a pressure filter to obtain solid precipitate, mixing solid precipitate and mixed solvent, mixing the nimbin extract and solvent C according to mass ratio of 1:1-3, washing the solid precipitate using solvent C, collecting leachate, and drying the leachate.