The present application relates to a crystalline sulfamide compound, and in particular relates to a crystalline (S)-N-((S)-1-(2-chlorphenyl)-2-((3, 3-difluorocyclobutyl) amido)-2 oxoethyl)-2-(4-cyanopyridin-2-base)-N-(3-fluorophenyl)-isothiazolidine-3-formamide 1, 1-dioxide, and a preparation method therefor, a crystalline composition, a pharmaceutical composition and uses thereof. An X-ray powder diffraction spectrum of a crystalline hydrate of formula II of the present application has diffraction peaks at positions of about 14.40°, 20.28°, 20.94°, 22.02°and 24.46°, represented by 2θ. The crystalline hydrate of formula II of the present application has good IDH1 inhibitory activity and performs high stability, and therefore has advantages in physical property, safety and metabolic stability, and has high medicine value.