Method for producing granular compound fertilizer

The invention provides a method for producing granular compound fertilizer. The method comprises the following steps: 1) mixing raw materials to form a raw material system, wherein the raw materials comprise two or three out of nitrogen fertilizer, phosphate fertilizer and potassium fertilizer and binder, and the mass content of water-insoluble substances is lower than 5% in the mixed raw material system; and 2) granulating the raw material system into the granular compound fertilizer. Compared with the existing method for producing granular compound fertilizer, the invention can guarantee the granulating effect and ensure that the composite fertilizer is applicable in irrigation and fertilization by using the raw materials with low content of the water-insoluble substances and the binder. Therefore, the granular compound fertilizer is favorable for the integral water-fertilizer fertilization of leaf vegetables, greenhouse crops and cash crops and mechanical fertilization and improves the utilization rate of the fertilizer.