NOVELTY - High-efficiency slow-release composite fertilizer comprises diatomite, dry cow manure, rice bran, urea, monoammonium phosphate, calcium superphosphate, vegetable gum, animal glue, basalt powder, potassium chloride, black soil, copper sulfate, zinc sulfate, pine needles, pregelatinized cassava starch, polyvinyl alcohol, glycerol, highly active zinc oxide, magnesium sulfate, egg shells, and additive. The additive comprises poultry feather, sulfuric acid solution, sodium hydroxide, keratinase, copper citrate, manganese citrate, zinc citrate, medical stone powder, and sodium silicate.    USE - High-efficiency slow-release composite fertilizer.    ADVANTAGE - The fertilizer has wide raw material source and low cost. The use of diatomite and slow-release coating agent in forming double-coated fertilizer nutrients prevents premature loss of nutrient, prolongs fertilizer effect, satisfies requirements for crop growth with single application, and simplifies planting cost.    DETAILED DESCRIPTION - High-efficiency slow-release composite fertilizer comprises 10-15 pts. wt. 1250-2000-mesh diatomite, 15-18 pts. wt. dry cow manure, 8-10 pts. wt. rice bran, 20-22 pts. wt. urea, 15-18 pts. wt. monoammonium phosphate, 8-10 pts. wt. calcium superphosphate, 2-3 pts. wt. vegetable gum, 1-3 pts. wt. animal glue, 1-2 pts. wt. basalt powder, 10-12 pts. wt. potassium chloride, 6-8 pts. wt. black soil, 1-2 pts. wt. copper sulfate, 2-4 pts. wt. zinc sulfate, 4-5 pts. wt. pine needles, 12-15 pts. wt. pregelatinized cassava starch, 6-8 pts. wt. polyvinyl alcohol, 4-5 pts. wt. glycerol, 0.1-0.2 pt. wt. highly active zinc oxide, 3-5 pts. wt. magnesium sulfate, 1-2 pts. wt. egg shells, and 4-5 pts. wt. additive. The additive comprises 12-15 pts. wt. poultry feather, 30-35 pts. wt. 30-40% sulfuric acid solution, sodium hydroxide, 0.15-0.2 pt. wt. keratinase, 1-2 pts. wt. copper citrate, 1-2 pts. wt. manganese citrate, 1-2 pts. wt. zinc citrate, 20-22 pts. wt. medical stone powder, and 5-6 pts. wt. sodium silicate. The additive is prepared by washing poultry feather with water, high-temperature sterilizing, crushing, adding sulfuric acid solution, hydrolyzing for 15-18 hours, adding sodium hydroxide solution to adjust pH to 6.5-7, heating to 50-60 degrees C, adding keratinase and performing enzymolysis for 12-15 hours, adding copper citrate, manganese citrate and zinc citrate, stirring for 2-3 hours, adding sodium silicate, continuously stirring for 30-40 minutes, adding medical stone powder, uniformly stirring, drying, and grinding for 40-50 minutes. An INDEPENDENT CLAIM is included for slow-release composite fertilizer production by:    (A) mixing dry cow manure, rice bran, pine needles and egg shells, crushing, adding water, and fermenting;    (B) mixing water with equal amount of diatomite, grinding for 20-30 minutes to prepare diatomite slurry, adding copper sulfate, zinc sulfate and magnesium sulfate, uniformly stirring, and dehydrating and drying to prepare diatomite coating material;    (C) mixing vegetable gum, animal glue, polyvinyl alcohol, pregelatinized cassava starch and glycerol, adding deionized water, heating to 40-60 degrees C, uniformly stirring until completely dissolved and dispersed, adding highly active zinc oxide, and continuously stirring for 1-2 hours to obtain slow-release coating agent; and    (D) uniformly mixing fermented material and diatomite coating material with the remaining raw materials, granulating, spraying slow-release coating agent on surface of granules, hot-air-drying, and cooling to room temperature.