NOVELTY - Method for preparing coated controlled release fertilizer, involves (a) preparing polyurethane solution by mixing polyisocyanate and polyhydric alcohols, and adding acetone as solvent to obtained solution, (b) adding polyurethane solution, turpentine oil and polyvinyl alcohol to a reaction kettle, stirring and forming coating liquid, and atomizing the coating liquid, (c) preheating fertilizer granule in fluidized bed, spraying the coating liquid on the fertilizer granule, and hot air drying coated granule, and (d) recovering the coating liquid.    USE - The method is useful for preparing coated controlled release fertilizer (claimed).    ADVANTAGE - The method environmentally-friendly prepares coated controlled release fertilizer which has strong resistance to mechanical damage and good film-forming properties, coats the fertilizer granule at a rate of 5-30%, and provides nutrients to different crops.    DETAILED DESCRIPTION - Method for preparing coated controlled release fertilizer, involves (a) preparing polyurethane solution by mixing polyisocyanate and polyhydric alcohols in a ratio of 0.9-1.5:1, and adding acetone as solvent to obtained reaction solution, (b) adding 100 parts polyurethane solution obtained in the step (a), 5-20 parts turpentine oil and 0.5-2 parts polyvinyl alcohol to a reaction kettle, stirring components in the reaction kettle at 50 degrees C for 1 hour and forming a coating liquid, and atomizing the coating liquid at 0.05-0.3 MPa using pressure pump, where the atomization speed is 5-20 ml/minute, (c) adding 1000-5000 parts fertilizer granule to fluidized bed through conveyor belt, preheating the fertilizer granule at 60 degrees C, spraying the coating liquid on the fertilizer granule for coating the fertilizer granule, hot air drying coated granule at 70-90 degrees C to obtain coated fertilizer granule, and circulating the coated fertilizer granule in fluidized bed continuously for 2-4 hours, to obtain product, and (d) recovering the coating liquid by condensing vapor of the coating liquid to recovery unit in the reaction vessel. The polyisocyanate is one of toluene diisocyanate, diphenylmethane diisocyanate and polymethylene polyphenyl isocyanate. The polyhydric alcohol is one of polyoxypropylene glycol, polytetrahydrofuran and copolymerized tetrahydrofuran-propylene oxide.