The invention relates to a preparation method of
fudosteine crystals, and belongs to the technical field of crystals. The technical scheme of the invention is that the preparation method of the
fudosteine crystals of which the main grain sizes are ranged from 180 to 220 microns comprises the following steps: 1, adding the
fudosteine to water, wherein the solution
solid-
liquid ratio is 0.5g / ml to 1.0g / ml, and continuously stirring and dissolving for 30 to 60 minutes at the temperature of 40 to 50 DEG C; 2, carrying out
filtration and decolorization; moving a filtrate into a crystallizer, lowering the temperature to 10-20 DEG C, wherein the
cooling rate is 5-20 DEG C / h, adding
crystal seeds to the crystallizer, cultivating the crystals for 1-2 hours; then carrying out fed-batch of organic solvents of which the weights are 4 to 10 times of that of water in initial solutions to the crystallizer, wherein the fed-batch rate is 2-10 mL / min, and cultivating the crystals for 1-3 hours; 3, filtering, and washing filter cakes by using washing solvents, finally
drying products, thus obtaining the fudosteine products with
uniform size distribution.