Method for preparing special fertilizer for barley

The invention relates to the technical field of chemical engineering and discloses a method for preparing a special fertilizer for barley. The method comprises the following steps of detecting amounts of various nutrients absorbed from the soil during the growth process of barley, analyzing the ratio of nutrients needed in growth of barley, reacting phosphoric acid with carbomite to generate an intermediate and reacting the intermediate with alkaline potassium salt. Parameters in the reaction are strictly controlled so that a part of potassium dihydrogen phosphate generated in the reaction is crystallized, the contents of nitrogen, phosphorus and potassium in the reaction liquid are adjusted to be in line with the barley growth requirements so that more barley products are harvested with the minimum fertilizer investment and the method has significant economic value.