摘要： Numerical simulations are performed to understand the variation of KDP crystal surface height by a rapid growth technique. The theoretical models used in numerical simulations couple the macroscopic transport of solute and impurities with the microscopic interfacial kinetics processes. Studies are specifically made to growth rate fluctuation at each growth interface subject to variations in crystal size, bulk supersaturation, rotation rate of the stirring paddle, and impurities. It is found that predicted interface moving speeds, equivalent to the growth rate, are uniformly distributed normal to each pyramidal and prismatic faces at macroscale by taking into account the interfacial kinetics process; however, they fluctuate wavily at microscale. The amplitude of growth rate fluctuation is on the order of micrometer. The fluctuation in growth rate will cause KDP crystal surface height variation and lead to the formation of micron-sized and nanosized inclusions in the crystals. Increasing crystal size and bulk supersaturation intensifies the fluctuation in the growth rate, which may reduce the quality of grown KDP crystal. Increasing paddle’s rotational speed can make the fluctuation of the growth rate decrease. The impurities influence the growth rate of the KDP prismatic face obviously. When impurities exist in solution, the growth rate of the prismatic face decreases greatly and the fluctuation of the growth rate is enhanced by 1 order of magnitude.