Abstract: Potassium dihydrogen phosphate, as an important inorganic functional compound, is widely used in various fields such as agriculture, industry, and medicine. The performance of the final product is largely determined by the crystallization process. This review systematically summarized the crystallization thermodynamics, kinetics, and crystal growth behavior of potassium dihydrogen phosphate, and the influence mechanisms of factors such as pH, impurity ions, chelating agents, and organic solvents on its crystallization process was analyzed in detail. Furthermore, a critical review of the key equipment and optimization practices of batch and continuous crystallizers employed in the industrial production of potassium dihydrogen phosphate was provided. The purpose of this paper is to offer comprehensive theoretical references and technical guidance for in-depth understanding of the crystallization process of potassium dihydrogen phosphate, optimizing industrial production processes, and thereby preparing high-quality potassium dihydrogen phosphate products.