The invention discloses a method for preparing ammonium hydrogen phosphate from enriched superphosphate. The method comprises the steps of decomposing powdered rock phosphate by virtue of implicit acid, reacting to obtain a Ca(H2PO4)2 and acid insoluble residue mixture as enriched superphosphate directly, and introducing ammonia gas into enriched superphosphate so as to obtain ammonium hydrogen phosphate, wherein implicit acid is ammonium chloride. According to the method, powdered rock phosphate is decomposed into the Ca(H2PO4)2 and acid insoluble residue mixture by virtue of implicit acid ina calcium chloride sub-molten salt system, the mixture is directly used as an enriched superphosphate product, and ammonia gas produced by decomposing rock phosphate by virtue of obtained enriched superphosphate and NH4Cl is taken as the raw material for preparing ammonium hydrogen phosphate with a relatively high value, so that the problem that the environment is polluted by emitted ammonia gasis solved; and meanwhile, the ammonia gas can be adequately utilized for preparing ammonium hydrogen phosphate with the relatively high value, so that the cyclic utilization of resources is realized,the production cost is lowered, substances such as phosphogypsum and harmful gas are not generated in the phosphorus chemical industry production process, and the technical reconstruction of phosphorus chemical industry is realized.