NOVELTY - Sustained-release fertilizer comprises urea, monoammonium phosphate, potassium sulfate, sodium carboxymethylcellulose, fermented chicken manure, carbon powder, calcium superphosphate, diatomite, solid microbial inoculum, and sensitive hydrogel, where sensitive hydrogel comprises polymerizable monomer, N, Nmethylenebisacrylamide as crosslinking agent, ketoglutarate as photoinitiator, and polyvinyl alcohol or chitosan solution as polymer additive, and is prepared using photo polymerization method.    USE - The sustained-release fertilizer is useful for growing crop.    ADVANTAGE - The sustained-release fertilizer is rich in nutrients.    DETAILED DESCRIPTION - Sustained-release fertilizer comprises 20-25 pts. wt. urea, 20-25 pts. wt. monoammonium phosphate, 18-20 pts. wt. potassium sulfate, 15-25 pts. wt. 80-100 sodium carboxymethylcellulose, 30-40 pts. wt. fermented chicken manure, 15-25 pts. wt. carbon powder, 10-20 pts. wt. calcium superphosphate, 10-20 pts. wt. diatomite, 5-15 pts. wt. solid microbial inoculum, and 5-15 pts. wt. sensitive hydrogel, where sensitive hydrogel comprises polymerizable monomer which is one or more chosen from diacetone acrylamide, acrylamide, acrylic acid, and their mixtures, N, N-methylenebisacrylamide as cross-linking agent, 2-ketoglutarate as photoinitiator, and polyvinyl alcohol or chitosan solution as polymer additive, and is prepared using photo polymerization method. An INDEPENDENT CLAIM is included for preparing sustained-release fertilizer, which involves (a) weighing the above-mentioned raw materials, (b) uniformly mixing, and crushing urea, monoammonium phosphate and potassium sulfate, sieving the crushed mixture through 400-600 mesh size sieve, adding carbon powder, uniformly stirring, again adding sodium, uniformly mixing, granulating the mixture using disc granulator, sieving granule, drying sieved granule to 1.5-2.5 mm in diameter, and granulating unqualified granule, (c) adding 3-6 pts. wt. calcium superphosphate and 3-6 pts. wt. diatomite mixture, crushing the mixture, sieving the crushed mixture through 400-600 mesh size sieve, uniformly stirring, granulating the mixture with the granule obtained in step (b), sieving granule, drying sieved granule to 2.5-3.5 mm in diameter, and granulating unqualified granule, (d) crushing fermented chicken manure, uniformly stirring, sieving the crushed mixture through 400-600 mesh size sieve, granulating the mixture with the granule obtained in step (c), sieving granule, drying sieved granule to 3.5-4.5 mm in diameter, and granulating unqualified granule, (e) adding solid microbial inoculum with granule obtained in step (d) to disc granulator, and rolling and granulating until the granule is completely wrapped with microbial inoculum, (f) adding 7-14 pts. wt. calcium superphosphate and 7-14 pts. wt. diatomite mixture, crushing the mixture, uniformly stirring, sieving the crushed mixture through 400-600 mesh size sieve, granulating the mixture with the granule obtained in step (e), sieving granule, drying sieved granule to 4.5-5.5 mm in diameter, and granulating unqualified granule, and (g) adding sensitive hydrogel to the granule with sensitive hydrogel, and drying the wrapped granule at low temperature.