The invention relates to the technical field of pesticides, and in particular relatesto a herbicide composition containing mesotrione, florasulam and metolachlor. The herbicide composition comprises active ingredients and auxiliary materials, wherein the active ingredients comprise the following components in parts by weight: 1-80 parts of mesotrione, 0.1-10 parts of florasulam and 10-90 parts of metolachlor; the auxiliary materials comprise one or more of a safener, a wetting agent, a dispersant, a thickener, an anti-freezing agent, a preservative, a thixotropic agent, a defoaming agent, a disintegrating agent, a binder, a carrier and a solvent; the amount of the active ingredients accounts for 1%-99% of the total amount of the composition. The herbicide composition provided by the invention has good control effect, can become effective quickly, can kill weeds thoroughly, can be used for controlling weeds in a corn field effectively, can be prepared in the form of a suspension emulsion, a dispersible oil suspension, wettable powder or water dispersible granules, can be taken as a herbicide for treating stems and leaves in a corn field, and has closed weed control effect.