The invention discloses a medium trace element containing cowhair keratin coated slow-released fertilizer. The medium trace element containing cowhair keratin coated slow-released fertilizer is prepared from, by weight, 20-21 parts of cowhair, 40-45 parts of peanut bran, 50-52 parts of sugar residues, 35-37 parts of corn residues, 45-50 parts of peel, 18-19 parts of spirulina powder, 20-22 parts of kieselguhr, 20-22 parts of clay, 1-1.2 parts of itaconic acid, 1.5-2 parts of calcium bicarbonate, 1.2-1.3 parts of magnesium sulfate, 1-1.1 parts of manganese sulfate, 0.8-0.9 part of ammonium molybdate, 0.2-0.3 part of fatty acid methyl ester ethoxylate, 0.2-0.3 part of sodium carbonate, 20-21 parts of mercaptoethanol, 18-19 parts of urea, 3-4 parts of lauryl sodium sulfate, 0.2-0.3 part of transglutaminase, 3-4 parts of starch, 18-20 parts of 10% polyvinyl alcohol solution, 7-8 parts of 5% carboxymethylcellulose solution, 4-5 parts of formaldehyde, 5-6 parts of glycerin, 0.2-0.3 part of boron and 2-2.5 parts of microorganism bacterial powder. The medium trace element containing cowhair keratin coated slow-released fertilizer contains rich medium trace elements and is high in fertilizer efficiency, the fertilize absorption level of crops can be improved, the yield can be increased, and the quality can be improved.