The present invention pertains to the technical field of herbicide crystallization processes, and particularly relates to a triazolesulcotrione crystal form B, a preparation method therefor, and a use thereof. The triazolesulcotrione crystal form B has an X-ray powder diffraction pattern with characteristic peaks at a diffraction angle of 2θ of 7.1, 7.3, 9.6, 11.8, 13.4, 14.2, 14.6, 14.9, 18.2, 18.8, 19.1, 19.6, 19.9, 21.0, 21.4, 21.7, 22.6, 24.1, 24.4, 25.1, 25.8, 26.4, 27.2, 27.7, 28.0, 28.6, 29.4, 32.1, 34.7, 35.9, 36.8, 38.8, 39.3, and 39.7 degrees, a 2θ error range falling within ± 0.2°. The triazolesulcotrione crystal form B of the present invention has good stability, and the crystal form B or a compound composition of the crystal form B with other active ingredients has good control effect on gramineous weeds and some broadleaf weeds in rice paddy, significantly superior to those of a crystal form A.
