Abstract: To broaden pharmaceutical applications of the plant hormone abscisic acid （ABA） and establish an efficient preparation technology, ABA solubility thermodynamics, antisolvent crystallization kinetics, and purification processes were systematically investigated in ethanol-water cosolvents. ABA solubility, determined at 278.15~318.15 K in ethanol-water mixtures with various solvent ratios using a static equilibrium method, increased with temperature but decreased with an increasing water mole fraction. Molecular dynamics simulations were performed, and radial distribution function analysis was used to elucidate the intermolecular interaction mechanisms and ABA dissolution behavior in the ethanol-water cosolvent system. Antisolvent crystallization kinetic characteristics were experimentally investigated, allowing the establishment of nucleation and growth kinetic models through data regression fitting. Based on thermodynamic and kinetic laws, the effects of key process parameters on the ABA crystallization process and product quality were explored to determine the optimized process conditions. Under optimized conditions, ABA crystallization product with a purity of 98.70% was prepared with a yield of 81.20%, while the impurity content dropped by 35%, and the obtained crystals exhibit well-defined particle morphology.