Abstract: Two main methods of preparing potassium dihydrogen phosphate from wet-process phosphoric acid were briefly introduced.The method of purifying the wet-process phosphoric acid before preparation is reviewed.Its application is under restrictions because of the organic solvent′s high costs or difficult recycling.Besides，the methods of reacting wet-process phosphoric acid directly include electrolysis method，ion exchange method，double decomposition method，and multi-step method.Among them，the multi-step method produces the intermediate products before the target product，combining the purification of wet-process phosphoric acid with the production of potassium dihydrogen phosphate as a whole，and manufacturing qualified industrial grade product in lower cost.By comparison，it′s found that the multi-step method is more competitive with the broad development prospect.

Key words: wet-process phosphoric acid, potassium dihydrogen phosphate, multi-step method