This application relates to a method for preparing crystalline D-
psicose. In this application, crystalline D-
psicose is prepared by combining an
evaporation crystallization method with a cooling
crystallization method, which simplifies the preparation process, facilitates operation, and reduces
crystallization time. In this application, a
seed crystal is added when the solids content is relatively low (70-75%) during the
evaporation crystallization process. This facilitates crystallization, uniformizes the
crystal growth rate in each direction, shortens the overall crystallization time, and reduces
energy consumption. After
evaporation crystallization is complete,
crystal shaping is carried out to achieve uniform
crystal size, a smooth crystal surface, and a refined crystal form.After crystal regulation, crystallization by cooling is carried out, and the cooling frequency at specific intervals is designed based on the metastable region curve of D-
psicose. Once crystallization is completed using the preparation method described in this application, the resulting crystal exhibits high yield, a narrow
crystal size distribution, a
smooth surface, a mirror-like surface, good
reflectivity, and a regular crystal form.