Urea phosphate production method

The invention relates to a urea phosphate production method, belonging to the field of chemical techniques. The technical problem solved by the invention is to provide a urea phosphate production method which is lower in production cost. The urea phosphate production method provided by the invention comprises the following steps of: a, mixed acidic solution preparation: adding a sulfuric acid into a phosphoric acid solution so as to obtain a mixed acidic solution; b, slurry preparation: heating the mixed acidic solution to 75-95 DEG C, then adding a reaction amount of urea into the mixed acidic solution, and stirring the obtained mixture so as to react the mixture, thereby obtaining a slurry; c, primary cooling crystallization: cooling the slurry to 45-65 DEG C so as to obtain a crystal-containing solution, filtering the crystal-containing solution so as to obtain crystals and filtrate, and then drying the obtained crystals so as to obtain urea phosphates; and d, secondary cooling crystallization: cooling the filtrate obtained in the step c to 20-25 DEG C, separating supernatant liquid to obtain lower thick liquid, mixing the lower thick liquid with the slurry obtained in the step b, and then operating the obtained mixture according to the step c.