Preparation method of high-stability mesotrione-atrazine water suspension

The invention belongs to the field of pesticide and relates to a preparation method of a high-stability mesotrione-atrazine water suspension. The preparation method comprises 1, mixing mesotrione, an organic solvent and a dispersant, carrying out homogenization, and carrying out grinding by a grinding machine until particle size D98 is less than or equal to 4 micrometers so that a system A is obtained, 2, preparing an atrazine suspension with particle size D98 less than or equal to 4 micrometers as a system B, and 3, fast stirring to disperse the system B, slowly adding the system A into the system B according to a mass percentage of 1: 8-10, and mixing the system A and the system B to obtain the uniform high-stability mesotrione-atrazine water suspension. In the high-stability mesotrione-atrazine water suspension, mesotrione is isolated from an atrazine water phase system by an oil film so that a decomposition rate of mesotrione in the water phase system is reduced and the problem of severe decomposition of mesotrione in water is solved.