Method for producing compound fertilizer from allantoin wastewater

The invention discloses a method for producing a compound fertilizer from allantoin wastewater and belongs to the field of a wastewater processing technology. The method comprises the following steps: adjusting pH value of allantoin wastewater to 6.5-7.0 by using ammonia; and reacting by adding iron chelate, polymerized boron, zinc chelate and humic acid. Mass ratio of allantoin wastewater to iron chelate to polymerized boron to zinc chelate to humic acid is 1:0.04-0.05:0.02-0.025:0.015-0.02:0.01-0.015. According to the method provided by the invention, active ingredients in allantoin production wastewater are comprehensively utilized, and multiple nutritional ingredients such as iron, boron, zinc, humic acid and the like which are essential to plants are introduced to synthesize the multifunctional compound fertilizer. By the method, the prominent problem of environmental protection in production of allantoin can be solved, and production costs of allantoin can be reduced. Equipment requirements are low, and the method is simple to operate. The compound fertilizer obtained by the method has good fertilizer efficiency and has a certain effect of increasing yield and preventing disease and pest injury.