The invention discloses biodegradable coated urea, and relates to a sustained-release fertilizer. The biodegradable coated urea is characterized in that: the granular urea is formed by spraying melted stearic acid and then applying mixed powder, and consists of the following raw materials in part by weight: 100 parts of granular urea, 0.5 to 2.0 parts of stearic acid for coating and 1 to 1.5 parts of mixed powder for applying powder, wherein the mixed powder for applying powder consists of the following raw materials in percentage by weight: 5 to 10 percent of calcium stearate, 30 to 50 percent of magnesium oxide and the balance of kieselguhr. The invention provides the biodegradable coated urea product, which has biodegradable coating material, has no pollution, can improve the utilization efficiency of the fertilizer and reduce the production cost, and has low investment and remarkable benefit; the coating material can be degraded under the action of soil microbes, so pollution of the coating material to the environment is avoided, and ecological balance is favorable; and the urea coated by the coating has good sustained-release effect and round granular appearance, the product has no peculiar smell, and the utilization rate of nitrogen fertilizers is averagely improved by 15 to 20 percent.