Solid urea is lifted by a hoist to a vibrating screen, where impurities are removed before entering the storage hopper. After being measured, it enters the melter, and the melted urine enters the buffer tank before being pumped to the primary mixing tank; Powdered potassium chloride and monoammonium phosphate are manually unpacked, then lifted, screened, and measured separately. Together with the filler, they are transported by a mixing conveyor belt into the mixing elevator and lifted to the mixing hopper. They are then transported by a screw conveyor to the mixing heater for steam preheating. The preheated material enters the 1 # mixing tank and is thoroughly mixed with urine before entering the 2 # mixing tank. The mixed molten slurry enters the granulation tower for granulation. The slurry sprayed from the top of the tower is automatically cooled by air and formed at the bottom of the tower. It enters the conveyor belt through a small funnel and is transported to the cooling machine. After cooling treatment, it is lifted by the elevator to the rotary screen for screening. The finished product is then coated and sent to the automatic packaging machine for packaging and storage; Large particles and fine powder are returned to the top of the tower for re recovery and granulation; The cooled exhaust gas is discharged after passing through the exhaust fan, cyclone dust collector, and washing.