NOVELTY - Modified acrylic acid-coated synergistic slow-release compound fertilizer comprises diatomite, castor shells, rapeseed meal, traditional Chinese medicine residues, bamboo shavings, zinc gluconate, ferrous sulfate, sodium thiosulfate, ethylene glycol dimethacrylate, corn bran, potassium chloride, urea, diammonium phosphate, lees, sodium dodecyl sulfate, acrylic acid, composted manure, soybean powder, zinc acetate, sodium acetate, and additive including poultry feather, sodium hydroxide, keratinase, copper citrate, manganese citrate, zinc citrate, medical stone powder and sodium silicate.    USE - Modified acrylic acid-coated synergistic slow-release compound fertilizer.    ADVANTAGE - The fertilizer is rich in nutrients and organic material, has synergistic effect, protects the soil, and improves soil fertility. The use of diatomite and slow-release coating agent in forming double-coated fertilizer nutrients prolongs fertilizer effect, increases fertilizer utilization rate, and improves crop yield.    DETAILED DESCRIPTION - Modified acrylic acid-coated synergistic slow-release compound fertilizer comprises 10-15 pts. wt. 1250-2000-mesh diatomite, 5-6 pts. wt. castor shells, 10-12 pts. wt. rapeseed meal, 4-5 pts. wt. traditional Chinese medicine residues, 5-6 pts. wt. bamboo shavings, 2-4 pts. wt. zinc gluconate, 3-4 pts. wt. ferrous sulfate, 2-3 pts. wt. sodium thiosulfate, 6-8 pts. wt. ethylene glycol dimethacrylate, 10-12 pts. wt. corn bran, 8-10 pts. wt. potassium chloride, 12-15 pts. wt. urea, 20-25 pts. wt. diammonium phosphate, 8-10 pts. wt. lees, 1-2 pts. wt. sodium dodecyl sulfate, 12-15 pts. wt. acrylic acid, 12-15 pts. wt. composted manure, 2-3 pts. wt. soybean powder, 2-4 pts. wt. zinc acetate, 1-2 pts. wt. sodium acetate, 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 compound fertilizer production by:    (A) uniformly mixing castor shells, rapeseed meal, Chinese medicine residues, corn bran and lees, crushing, mixing with bamboo shavings and soybean powder, adding water, and fermenting;    (B) mixing water and diatomite, grinding for 20-30 minutes to prepare diatomite slurry, adding zinc gluconate, ferrous sulfate and zinc acetate, stirring for 20-30 minutes, and drying to obtain diatomite coating material;    (C) mixing deionized water and acrylic acid, adding sodium dodecyl sulfate, stirring until completely dissolved and dispersing, heating to 60-80 degrees C, adding ethylene glycol dimethacrylate and sodium acetate, and stirring for 1.5-2 hours to obtain slow-release coating agent; and    (D) uniformly mixing materials obtained in steps (A) and (B) with the remaining raw materials, granulating, coating with slow-release coating agent, hot-air-drying, and cooling to room temperature.