The invention discloses a method for regulating nutrients of a diammonium phosphate product, and relates to diammonium phosphate fertilizer. The method comprises the following steps: removing certain water from the sludge filtered through the sewage treatment, calculating the sludge quantity required to be increased according to the slurry spraying quantity and adding the sludge into the returning charge for producing the diammonium phosphate to regulate the nutrients of the product. The water content removed from the sludge accounts for 7 percent of the total weight of the sludge. By using the method, the nitrogen content of the product can be enhanced, the phosphorus content can be reduced, the qualification rate of the product can be ensured, the sludge can be recovered and the environment can be improved and protected. Therefore, the method is suitable for manufacturer of diammonium phosphate.