This invention discloses a sustained-release chelated topdressing fertilizer containing secondary and trace elements. The sustained-release chelated topdressing fertilizer is composed of: urea 10-50 parts, ammonium sulfate 0-30 parts, ammonium chloride 0-35 parts, potassium chloride 0-30 parts, potassium sulfate 0-40 parts, calcium amino acid chelate 0-1 part, magnesium amino acid chelate 0-1 part, ferric amino acid chelate 0-1 part, zinc amino acid chelate 0-1 part, copper amino acid chelate 0-0.2 part, molybdenum amino acid chelate 0-0.1 part, manganese amino acid chelate 0-0.1 part, attapulgite 2-8 parts, borax 0-1 part, and dicyandiamide 0.02-0.1 part. The sustained-release nitrogen fertilizer has long effective period and high utilization rate of nitrogen, and can supplement necessary secondary and trace elements to crops. Crops applied with the sustained-release nitrogen fertilizer have such advantages as high yield, high quality, and no deficiency or loss of nitrogen in late period.