Continuous crystallization technology has attracted rising attention from chemists and material scientists. In this paper, cefminox sodium is selected as a model drug for consecutive antisolvent crystallization using a multistage mixed suspension mixed product removal (MSMPR) crystallizer. The effects of operating parameters on the product crystal particle size, crystal habit, and yield under steady‐state conditions are investigated in detail: operating parameters such as the initial concentration of the crystallization solution, the volume ratio of the crystallization solution to antisolvent, the total flow rate, the amount of seed crystals added, the crystallization temperature, and the mixing rate. The kinetic solubility data of cefminox sodium in two binary aqueous mixed solvents at 278.15–303.15 K are determined by laser dynamic method, and two empirical models are subsequently borrowed to fit the obtained data. This work provides a new crystallization process for cefminox sodium. After optimization, the mass yield is increased to 89.11%, the average particle size Dv(50) is about 164 µm. [ABSTRACT FROM AUTHOR]