An amorphous biscarfentrazone and a preparation method and use thereof are provided. The X-ray powder diffraction pattern of the amorphous biscarfentrazone is free of acute diffraction peaks, and preferably is substantially as shown in Fig. 2. The amorphous biscarfentrazone has a better physicochemical stability than the crystalline form A of biscarfentrazone, and no crystalline transformation occurred within two months of storage at a high temperature of 55°C, purity was not substantially reduced, and water solubility doubled. The amorphous biscarfentrazone and a composition of the amorphous biscarfentrazone compounded with other effective ingredients have a better prevention and killing effect both on broad-leaved weeds and certain gramineous weeds found in wheat fields, and so have good application prospects.
